diff --git a/tests/test_ditem.py b/tests/test_ditem.py
new file mode 100644
index 0000000..5636add
--- /dev/null
+++ b/tests/test_ditem.py
@@ -0,0 +1,204 @@
+#!/usr/bin/env python
+# -*- coding: UTF-8 -*-
+
+"""Contains test cases for the DownloadItem object."""
+
+from __future__ import unicode_literals
+
+import sys
+import os.path
+import unittest
+
+PATH = os.path.realpath(os.path.abspath(__file__))
+sys.path.insert(0, os.path.dirname(os.path.dirname(PATH)))
+
+try:
+    from youtube_dl_gui.downloadmanager import DownloadItem
+except ImportError as error:
+    print error
+    sys.exit(1)
+
+
+class TestItemInit(unittest.TestCase):
+
+    """Test case for DownloadItem init."""
+
+    def test_init(self):
+        url = "url"
+        options = ["-f", "flv"]
+
+        ditem = DownloadItem(url, options)
+
+        self.assertEqual(ditem.stage, "Queued")
+        self.assertEqual(ditem.url, url)
+        self.assertEqual(ditem.options, options)
+        self.assertEqual(ditem.object_id, hash(url + unicode(options)))
+
+        self.assertEqual(ditem.path, "")
+        self.assertEqual(ditem.filenames, [])
+        self.assertEqual(ditem.extensions, [])
+
+        self.assertEqual(
+            ditem.progress_stats,
+            {"filename": url,
+             "extension": "-",
+             "filesize": "-",
+             "percent": "0%",
+             "speed": "-",
+             "eta": "-",
+             "status": "Queued"}
+        )
+
+
+class TestGetFiles(unittest.TestCase):
+
+    """Test case for DownloadItem get_files method."""
+
+    def setUp(self):
+        self.ditem = DownloadItem("url", ["-f", "flv"])
+
+    def test_get_files(self):
+        path = os.path.join("/home", "user", "downloads")
+
+        self.ditem.path = path
+        self.ditem.filenames = ["file1", "file2"]
+        self.ditem.extensions = [".mp4", ".m4a"]
+
+        self.assertEqual(self.ditem.get_files(), [os.path.join(path, "file1", ".mp4"), os.path.join(path, "file2", ".m4a")])
+
+    def test_get_files_no_data(self):
+        self.assertEqual(self.ditem.get_files(), [])
+
+
+class TestItemComparison(unittest.TestCase):
+
+    """Test case for DownloadItem __eq__ method."""
+
+    def test_equal_true(self):
+        ditem1 = DownloadItem("url", ["-f", "flv"])
+        ditem2 = DownloadItem("url", ["-f", "flv"])
+
+        self.assertTrue(ditem1 == ditem2)
+
+    def test_equal_false(self):
+        ditem1 = DownloadItem("url", ["-f", "flv"])
+        ditem2 = DownloadItem("url2", ["-f", "flv"])
+
+        self.assertFalse(ditem1 == ditem2)
+
+        ditem1 = DownloadItem("url", ["-f", "flv"])
+        ditem2 = DownloadItem("url", ["-f", "mp4"])
+
+        self.assertFalse(ditem1 == ditem2)
+
+
+class TestSetItemStage(unittest.TestCase):
+
+    """Test case for DownloadItem stage setter."""
+
+    def setUp(self):
+        self.ditem = DownloadItem("url", ["-f", "flv"])
+
+    def test_set_stage_valid(self):
+        self.ditem.stage = "Queued"
+        self.assertEqual(self.ditem.stage, "Queued")
+
+        self.ditem.stage = "Active"
+        self.assertEqual(self.ditem.stage, "Active")
+
+        self.ditem.stage = "Completed"
+        self.assertEqual(self.ditem.stage, "Completed")
+
+        self.ditem.stage = "Paused"
+        self.assertEqual(self.ditem.stage, "Paused")
+
+    def test_set_stage_invalid(self):
+        raised = False
+
+        try:
+            self.ditem.stage = "some other status"
+        except ValueError:
+            raised = True
+
+        self.assertTrue(raised)
+
+
+class TestUpdateStats(unittest.TestCase):
+
+    """Test case for DownloadItem update_stats method."""
+
+    def setUp(self):
+        self.ditem = DownloadItem("url", ["-f", "flv"])
+
+    def test_update_stats(self):
+        path = os.path.join("/home", "user")
+
+        self.ditem.update_stats({"filename": "somefilename",
+                                 "extension": ".mp4",
+                                 "filesize": "9.45MiB",
+                                 "percent": "2.0%",
+                                 "speed": "200.00KiB/s",
+                                 "eta": "00:38",
+                                 "status": "Downloading",
+                                 "path": path})
+
+        self.assertEqual(self.ditem.path, path)
+        self.assertEqual(self.ditem.filenames, ["somefilename"])
+        self.assertEqual(self.ditem.extensions, [".mp4"])
+        self.assertEqual(
+            self.ditem.progress_stats,
+            {"filename": "somefilename",
+             "extension": ".mp4",
+             "filesize": "9.45MiB",
+             "percent": "2.0%",
+             "speed": "200.00KiB/s",
+             "eta": "00:38",
+             "status": "Downloading"}
+        )
+
+        self.ditem.update_stats({"filename": "someotherfilename", "extension": ".m4a"})
+
+        self.assertEqual(self.ditem.filenames, ["somefilename", "someotherfilename"])
+        self.assertEqual(self.ditem.extensions, [".mp4", ".m4a"])
+        self.assertEqual(
+            self.ditem.progress_stats,
+            {"filename": "someotherfilename",
+             "extension": ".m4a",
+             "filesize": "9.45MiB",
+             "percent": "2.0%",
+             "speed": "200.00KiB/s",
+             "eta": "00:38",
+             "status": "Downloading"}
+        )
+
+    def test_update_stats_invalid_input(self):
+        self.assertRaises(AssertionError, self.ditem.update_stats, [])
+
+
+class TestDownloadItemPrivate(unittest.TestCase):
+
+    """Test case for private method of the DownloadItem."""
+
+    def test_set_stage(self):
+        ditem = DownloadItem("url", ["-f", "flv"])
+
+        active_status = ["Pre Processing", "Downloading", "Post Processing"]
+        complete_status = ["Finished", "Error", "Warning", "Stopped", "Already Downloaded", "Filesize Abort"]
+
+        for status in active_status:
+            ditem._stage = "Queued"
+            ditem._set_stage(status)
+            self.assertEqual(ditem.stage, "Active")
+
+        for status in complete_status:
+            ditem._stage = "Active"
+            ditem._set_stage(status)
+            self.assertEqual(ditem.stage, "Completed")
+
+
+def main():
+    unittest.main()
+
+
+if __name__ == '__main__':
+    main()
diff --git a/tests/test_dlist.py b/tests/test_dlist.py
new file mode 100644
index 0000000..0d5eec8
--- /dev/null
+++ b/tests/test_dlist.py
@@ -0,0 +1,231 @@
+#!/usr/bin/env python
+# -*- coding: UTF-8 -*-
+
+"""Contains test cases for the DownloadList object."""
+
+import sys
+import os.path
+import unittest
+
+PATH = os.path.realpath(os.path.abspath(__file__))
+sys.path.insert(0, os.path.dirname(os.path.dirname(PATH)))
+
+try:
+    import mock
+    from youtube_dl_gui.downloadmanager import DownloadList, synchronized
+except ImportError as error:
+    print error
+    sys.exit(1)
+
+
+class TestInit(unittest.TestCase):
+
+    """Test case for the DownloadList init."""
+
+    def test_init(self):
+        mocks = [mock.Mock(object_id=0), mock.Mock(object_id=1)]
+
+        dlist = DownloadList(mocks)
+        self.assertEqual(dlist._items_list, [0, 1])
+        self.assertEqual(dlist._items_dict, {0: mocks[0], 1: mocks[1]})
+
+    def test_init_empty(self):
+        dlist = DownloadList()
+        self.assertEqual(dlist._items_list, [])
+        self.assertEqual(dlist._items_dict, {})
+
+    def test_init_invalid_args(self):
+        self.assertRaises(AssertionError, DownloadList, {})
+        self.assertRaises(AssertionError, DownloadList, ())
+        self.assertRaises(AssertionError, DownloadList, False)
+
+
+class TestInsert(unittest.TestCase):
+
+    """Test case for the DownloadList insert method."""
+
+    def test_insert(self):
+        mock_ditem = mock.Mock(object_id=0)
+
+        dlist = DownloadList()
+        dlist.insert(mock_ditem)
+
+        self.assertEqual(dlist._items_list, [0])
+        self.assertEqual(dlist._items_dict, {0: mock_ditem})
+
+
+class TestRemove(unittest.TestCase):
+
+    """Test case for the DownloadList remove method."""
+
+    def setUp(self):
+        self.mocks = [mock.Mock(object_id=0), mock.Mock(object_id=1), mock.Mock(object_id=2)]
+        self.dlist = DownloadList(self.mocks)
+
+    def test_remove(self):
+        self.assertTrue(self.dlist.remove(1))
+
+        self.assertEqual(self.dlist._items_list, [0, 2])
+        self.assertEqual(self.dlist._items_dict, {0: self.mocks[0], 2: self.mocks[2]})
+
+    def test_remove_not_exist(self):
+        self.assertRaises(KeyError, self.dlist.remove, 3)
+
+    def test_remove_active(self):
+        self.mocks[1].stage = "Active"
+
+        self.assertFalse(self.dlist.remove(1))
+        self.assertEqual(self.dlist._items_list, [0, 1, 2])
+        self.assertEqual(self.dlist._items_dict, {0: self.mocks[0], 1: self.mocks[1], 2: self.mocks[2]})
+
+
+class TestFetchNext(unittest.TestCase):
+
+    """Test case for the DownloadList fetch_next method."""
+
+    def test_fetch_next(self):
+        items_count = 3
+
+        mocks = [mock.Mock(object_id=i, stage="Queued") for i in range(items_count)]
+
+        dlist = DownloadList(mocks)
+
+        for i in range(items_count):
+            self.assertEqual(dlist.fetch_next(), mocks[i])
+            mocks[i].stage = "Active"
+
+        self.assertIsNone(dlist.fetch_next())
+
+        for i in range(items_count):
+            mocks[i].stage = "Completed"
+
+        self.assertIsNone(dlist.fetch_next())
+
+        mocks[1].stage = "Queued"  # Re-queue item
+        self.assertEqual(dlist.fetch_next(), mocks[1])
+
+    def test_fetch_next_empty_list(self):
+        dlist = DownloadList()
+        self.assertIsNone(dlist.fetch_next())
+
+
+class TestMoveUp(unittest.TestCase):
+
+    """Test case for the DownloadList move_up method."""
+
+    def setUp(self):
+        mocks = [mock.Mock(object_id=i, stage="Queued") for i in range(3)]
+        self.dlist = DownloadList(mocks)
+
+    def test_move_up(self):
+        self.dlist.move_up(1)
+        self.assertEqual(self.dlist._items_list, [1, 0, 2])
+
+    def test_move_up_already_on_top(self):
+        self.dlist.move_up(0)
+        self.assertEqual(self.dlist._items_list, [0, 1, 2])
+
+    def test_move_up_not_exist(self):
+        self.assertRaises(ValueError, self.dlist.move_up, 666)
+
+
+class TestMoveDown(unittest.TestCase):
+
+    """Test case for the DownloadList move_down method."""
+
+    def setUp(self):
+        mocks = [mock.Mock(object_id=i, stage="Queued") for i in range(3)]
+        self.dlist = DownloadList(mocks)
+
+    def test_move_down(self):
+        self.dlist.move_down(1)
+        self.assertEqual(self.dlist._items_list, [0, 2, 1])
+
+    def test_move_down_already_on_bottom(self):
+        self.dlist.move_down(2)
+        self.assertEqual(self.dlist._items_list, [0, 1, 2])
+
+    def test_move_down_not_exist(self):
+        self.assertRaises(ValueError, self.dlist.move_down, 666)
+
+
+class TestGetItem(unittest.TestCase):
+
+    """Test case for the DownloadList get_item method."""
+
+    def test_get_item(self):
+        mocks = [mock.Mock(object_id=i) for i in range(3)]
+        dlist = DownloadList(mocks)
+
+        self.assertEqual(dlist.get_item(0), mocks[0])
+        self.assertEqual(dlist.get_item(2), mocks[2])
+
+    def test_get_item_not_exist(self):
+        dlist = DownloadList()
+        self.assertRaises(KeyError, dlist.get_item, 0)
+
+
+class TestGetLength(unittest.TestCase):
+
+    """Test case for the DownloadList __len__ method."""
+
+    def test_get_length(self):
+        dlist = DownloadList([mock.Mock(), mock.Mock()])
+        self.assertEqual(len(dlist), 2)
+
+    def test_get_length_empty_list(self):
+        dlist = DownloadList()
+        self.assertEqual(len(dlist), 0)
+
+
+class TestHasItem(unittest.TestCase):
+
+    """Test case for the DownloadList has_item method."""
+
+    def setUp(self):
+        mock_ditem = mock.Mock(object_id=1337)
+        self.dlist = DownloadList([mock_ditem])
+
+    def test_has_item_true(self):
+        self.assertTrue(self.dlist.has_item(1337))
+
+    def test_has_item_false(self):
+        self.assertFalse(self.dlist.has_item(1000))
+
+
+class TestGetItems(unittest.TestCase):
+
+    """Test case for the DownloadList get_items method."""
+
+    def test_get_items(self):
+        mocks = [mock.Mock() for _ in range(3)]
+        dlist = DownloadList(mocks)
+
+        self.assertEqual(dlist.get_items(), mocks)
+
+    def test_get_items_empty_list(self):
+        dlist = DownloadList()
+        self.assertEqual(dlist.get_items(), [])
+
+
+class TestSynchronizeDecorator(unittest.TestCase):
+
+    def test_synchronize(self):
+        mock_func = mock.Mock()
+        mock_lock = mock.Mock()
+
+        decorated_func = synchronized(mock_lock)(mock_func)
+
+        self.assertEqual(decorated_func(1, a=2), mock_func.return_value)
+
+        mock_func.assert_called_once_with(1, a=2)
+        mock_lock.acquire.assert_called_once()
+        mock_lock.release.assert_called_once()
+
+
+def main():
+    unittest.main()
+
+
+if __name__ == '__main__':
+    main()
diff --git a/youtube_dl_gui/downloadmanager.py b/youtube_dl_gui/downloadmanager.py
index a97c247..e24ca99 100644
--- a/youtube_dl_gui/downloadmanager.py
+++ b/youtube_dl_gui/downloadmanager.py
@@ -26,6 +26,7 @@ import os.path
 
 from threading import (
     Thread,
+    RLock,
     Lock
 )
 
@@ -39,13 +40,226 @@ from .downloaders import YoutubeDLDownloader
 
 from .utils import (
     YOUTUBEDL_BIN,
-    os_path_exists
+    os_path_exists,
+    to_string
 )
 
 
 MANAGER_PUB_TOPIC = 'dlmanager'
 WORKER_PUB_TOPIC = 'dlworker'
 
+_SYNC_LOCK = RLock()
+
+# Decorator that adds thread synchronization to a function
+def synchronized(lock):
+    def _decorator(func):
+        def _wrapper(*args, **kwargs):
+            lock.acquire()
+            ret_value = func(*args, **kwargs)
+            lock.release()
+            return ret_value
+        return _wrapper
+    return _decorator
+
+
+class DownloadItem(object):
+
+    """Object that represents a download.
+
+    Attributes:
+        STAGES (tuple): Main stages of the download item.
+
+        ACTIVE_STAGES (tuple): Sub stages of the 'Active' stage.
+
+        COMPLETED_STAGES (tuple): Sub stages of the 'Completed' stage.
+
+    Args:
+        url (string): URL that corresponds to the download item.
+
+        options (list): Options list to use during the download phase.
+
+    """
+
+    STAGES = ("Queued", "Active", "Paused", "Completed")
+
+    ACTIVE_STAGES = ("Pre Processing", "Downloading", "Post Processing")
+
+    COMPLETED_STAGES = ("Finished", "Error", "Warning", "Stopped", "Already Downloaded", "Filesize Abort")
+
+    def __init__(self, url, options):
+        self.url = url
+        self.options = options
+        self._stage = self.STAGES[0]
+
+        self.object_id = hash(url + to_string(options))
+
+        self.path = ""
+        self.filenames = []
+        self.extensions = []
+
+        self.progress_stats = {
+            "filename": url,
+            "extension": "-",
+            "filesize": "-",
+            "percent": "0%",
+            "speed": "-",
+            "eta": "-",
+            "status": self.stage
+        }
+
+    @property
+    def stage(self):
+        return self._stage
+
+    @stage.setter
+    def stage(self, value):
+        if value not in self.STAGES:
+            raise ValueError(value)
+
+        self._stage = value
+
+    def get_files(self):
+        """Returns a list that contains all the system files bind to this object."""
+        files = []
+
+        for index, item in enumerate(self.filenames):
+            path = os.path.join(self.path, item, self.extensions[index])
+            files.append(path)
+
+        return files
+
+    def update_stats(self, stats_dict):
+        """Updates the progress_stats dict from the given dictionary."""
+        assert isinstance(stats_dict, dict)
+
+        for key in stats_dict:
+            if key in self.progress_stats:
+                self.progress_stats[key] = stats_dict[key]
+
+            # Extract extra stuff
+            if key == "filename":
+                if stats_dict[key] not in self.filenames:
+                    self.filenames.append(stats_dict[key])
+
+            if key == "extension":
+                if stats_dict[key] not in self.extensions:
+                    self.extensions.append(stats_dict[key])
+
+            if key == "path":
+                self.path = stats_dict[key]
+
+            if key == "status":
+                self._set_stage(stats_dict[key])
+
+    def _set_stage(self, status):
+        if status in self.ACTIVE_STAGES:
+            self._stage = self.STAGES[1]
+
+        if status in self.COMPLETED_STAGES:
+            self._stage = self.STAGES[3]
+
+    def __eq__(self, other):
+        return self.object_id == other.object_id
+
+
+
+class DownloadList(object):
+
+    """List like data structure that contains DownloadItems.
+
+    Args:
+        items (list): List that contains DownloadItems.
+
+    """
+
+    def __init__(self, items=None):
+        assert isinstance(items, list) or items is None
+
+        if items is None:
+            self._items_dict = {}  # Speed up lookup
+            self._items_list = []  # Keep the sequence
+        else:
+            self._items_list = [item.object_id for item in items]
+            self._items_dict = {item.object_id: item for item in items}
+
+    @synchronized(_SYNC_LOCK)
+    def insert(self, item):
+        """Inserts the given item to the list. Does not check for duplicates. """
+        self._items_list.append(item.object_id)
+        self._items_dict[item.object_id] = item
+
+    @synchronized(_SYNC_LOCK)
+    def remove(self, object_id):
+        """Removes an item from the list.
+
+        Removes the item with the corresponding object_id from
+        the list if the item is not in 'Active' state.
+
+        Returns:
+            True on success else False.
+
+        """
+        if self._items_dict[object_id].stage != "Active":
+            self._items_list.remove(object_id)
+            del self._items_dict[object_id]
+
+            return True
+        return False
+
+    @synchronized(_SYNC_LOCK)
+    def fetch_next(self):
+        """Returns the next queued item on the list.
+
+        Returns:
+            Next queued item or None if no other item exist.
+
+        """
+        for object_id in self._items_list:
+            cur_item = self._items_dict[object_id]
+
+            if cur_item.stage == "Queued":
+                return cur_item
+
+        return None
+
+    @synchronized(_SYNC_LOCK)
+    def move_up(self, object_id):
+        """Moves the item with the corresponding object_id up to the list."""
+        index = self._items_list.index(object_id)
+
+        if index > 0:
+            self._swap(index, index - 1)
+
+    @synchronized(_SYNC_LOCK)
+    def move_down(self, object_id):
+        """Moves the item with the corresponding object_id down to the list."""
+        index = self._items_list.index(object_id)
+
+        if index < (len(self._items_list) - 1):
+            self._swap(index, index + 1)
+
+    @synchronized(_SYNC_LOCK)
+    def get_item(self, object_id):
+        """Returns the DownloadItem with the given object_id."""
+        return self._items_dict[object_id]
+
+    @synchronized(_SYNC_LOCK)
+    def has_item(self, object_id):
+        """Returns True if the given object_id is in the list else False."""
+        return object_id in self._items_list
+
+    @synchronized(_SYNC_LOCK)
+    def get_items(self):
+        """Returns a list with all the items."""
+        return [self._items_dict[object_id] for object_id in self._items_list]
+
+    @synchronized(_SYNC_LOCK)
+    def __len__(self):
+        return len(self._items_list)
+
+    def _swap(self, index1, index2):
+        self._items_list[index1], self._items_list[index2] = self._items_list[index2], self._items_list[index1]
+
 
 class DownloadManager(Thread):