diff --git a/src/bitmessageqt/tests/__init__.py b/src/bitmessageqt/tests/__init__.py
index a81ddb047..27189e7a2 100644
--- a/src/bitmessageqt/tests/__init__.py
+++ b/src/bitmessageqt/tests/__init__.py
@@ -4,8 +4,15 @@
 from .main import TestMain, TestUISignaler
 from .settings import TestSettings
 from .support import TestSupport
+from .test_import import TestImports
+from .test_startup import TestStartup
+from .test_widgets import (
+    TestAddressValidator, TestLanguageBox, TestMessageView,
+    TestSafeHTMLParser
+)
 
 __all__ = [
-    "TestAddressbook", "TestMain", "TestSettings", "TestSupport",
-    "TestUISignaler"
+    "TestAddressbook", "TestAddressValidator", "TestLanguageBox",
+    "TestImports", "TestMain", "TestMessageView", "TestSafeHTMLParser",
+    "TestSettings", "TestStartup", "TestSupport", "TestUISignaler"
 ]
diff --git a/src/bitmessageqt/tests/main.py b/src/bitmessageqt/tests/main.py
index daf5d6d22..f8637b2b7 100644
--- a/src/bitmessageqt/tests/main.py
+++ b/src/bitmessageqt/tests/main.py
@@ -10,6 +10,36 @@
 from bitmessageqt import _translate, config, queues
 
 
+# pylint: disable=too-few-public-methods
+class TestApp(QtGui.QApplication):
+    """Lightweight QApplication subclass for tests, without the heavy
+    BitmessageQtApplication init (QLocalSocket singleton check,
+    organisation metadata, etc.)."""
+
+    @staticmethod
+    def get_windowstyle():
+        """Get window style set in config or default"""
+        return config.safeGet(
+            'bitmessagesettings', 'windowstyle',
+            'Windows' if sys.platform.startswith('win') else 'GTK+'
+        )
+
+
+def get_test_app():
+    """Return the existing QApplication or create a TestApp.
+
+    If the running app is a plain QApplication (missing get_windowstyle),
+    patch in the required methods from TestApp."""
+    app = QtGui.QApplication.instance()
+    if app is None:
+        return TestApp(sys.argv)
+    if not hasattr(app, 'get_windowstyle'):
+        # Bolt on the methods the tests expect; this happens when
+        # another test already created a bare QApplication.
+        app.get_windowstyle = TestApp.get_windowstyle
+    return app
+
+
 class TestBase(unittest.TestCase):
     """Base class for bitmessageqt test case"""
 
@@ -17,11 +47,10 @@ class TestBase(unittest.TestCase):
     def setUpClass(cls):
         """Provide the UI test cases with common settings"""
         cls.config = config
+        cls.app = get_test_app()
 
     def setUp(self):
-        self.app = (
-            QtGui.QApplication.instance()
-            or bitmessageqt.BitmessageQtApplication(sys.argv))
+        self.app = self.__class__.app
         self.window = self.app.activeWindow()
         if not self.window:
             self.window = bitmessageqt.MyForm()
diff --git a/src/bitmessageqt/tests/test_import.py b/src/bitmessageqt/tests/test_import.py
new file mode 100644
index 000000000..2e2bdb0da
--- /dev/null
+++ b/src/bitmessageqt/tests/test_import.py
@@ -0,0 +1,67 @@
+"""
+Smoke tests: verify that bitmessageqt modules can be imported.
+
+These tests require PyQt4 to be installed but do NOT need a running
+X server, database, or any bitmessage backend threads.
+"""
+import unittest
+
+
+# pylint: disable=import-error,unused-variable
+class TestImports(unittest.TestCase):
+    """Verify that key bitmessageqt modules are importable"""
+
+    @staticmethod
+    def test_import_bitmessageqt():
+        """The main bitmessageqt package should be importable"""
+        import bitmessageqt
+
+    @staticmethod
+    def test_import_bitmessageui():
+        """The generated UI module should be importable"""
+        from bitmessageqt import bitmessageui
+
+    @staticmethod
+    def test_import_settings():
+        """The settings dialog module should be importable"""
+        from bitmessageqt import settings
+
+    @staticmethod
+    def test_import_address_dialogs():
+        """The address dialogs module should be importable"""
+        from bitmessageqt import address_dialogs
+
+    @staticmethod
+    def test_import_networkstatus():
+        """The network status module should be importable"""
+        from bitmessageqt import networkstatus
+
+    @staticmethod
+    def test_import_safehtmlparser():
+        """safehtmlparser should be importable"""
+        from bitmessageqt import safehtmlparser
+
+    @staticmethod
+    def test_import_support():
+        """The support module should be importable"""
+        from bitmessageqt import support
+
+    @staticmethod
+    def test_import_foldertree():
+        """The foldertree module should be importable"""
+        from bitmessageqt import foldertree
+
+    @staticmethod
+    def test_import_messageview():
+        """The messageview module should be importable"""
+        from bitmessageqt import messageview
+
+    @staticmethod
+    def test_import_utils():
+        """The utils module should be importable"""
+        from bitmessageqt import utils
+
+    @staticmethod
+    def test_import_account():
+        """The account module should be importable"""
+        from bitmessageqt import account
diff --git a/src/bitmessageqt/tests/test_startup.py b/src/bitmessageqt/tests/test_startup.py
new file mode 100644
index 000000000..232702014
--- /dev/null
+++ b/src/bitmessageqt/tests/test_startup.py
@@ -0,0 +1,54 @@
+"""
+Smoke test: verify the main window can be created and shut down.
+
+This test requires the full bitmessage backend to be running
+(it is designed to run via ``bitmessagemain.py -t`` or from
+``src/tests/core.py``).  It also needs a display (Xvfb is fine).
+"""
+import sys
+import unittest
+
+try:
+    from PyQt4 import QtCore, QtGui
+    has_qt = True
+except ImportError:
+    has_qt = False
+
+
+@unittest.skipUnless(has_qt, "requires PyQt4")
+class TestStartup(unittest.TestCase):
+    """Verify the main window starts and has expected structure"""
+
+    def setUp(self):
+        import bitmessageqt
+        self.app = (
+            QtGui.QApplication.instance()
+            or bitmessageqt.BitmessageQtApplication(sys.argv))
+        self.window = self.app.activeWindow()
+        if not self.window:
+            self.window = bitmessageqt.MyForm()
+            self.window.appIndicatorInit(self.app)
+
+    def test_window_exists(self):
+        """The main window should be created successfully"""
+        self.assertIsNotNone(self.window)
+        self.assertIsNotNone(self.window.ui)
+
+    def test_window_has_tabs(self):
+        """The main window should have the expected tab widget"""
+        tabs = self.window.ui.tabWidget
+        self.assertIsNotNone(tabs)
+        self.assertGreater(tabs.count(), 0)
+
+    def test_window_title(self):
+        """The main window should have a non-empty title"""
+        self.assertTrue(len(self.window.windowTitle()) > 0)
+
+    def test_status_bar(self):
+        """The main window should have a status bar"""
+        self.assertIsNotNone(self.window.statusBar())
+
+    def test_quit_cycle(self):
+        """The event loop should start and stop without crashing"""
+        QtCore.QTimer.singleShot(50, self.app.quit)
+        self.app.exec_()
diff --git a/src/bitmessageqt/tests/test_widgets.py b/src/bitmessageqt/tests/test_widgets.py
new file mode 100644
index 000000000..6652072ff
--- /dev/null
+++ b/src/bitmessageqt/tests/test_widgets.py
@@ -0,0 +1,92 @@
+"""
+Unit tests for individual bitmessageqt widgets.
+
+These tests need a display (real or virtual via Xvfb/xvfb-run) and PyQt4,
+but do NOT require the full bitmessage backend, database, or network.
+Each test creates only the minimal widget under test.
+"""
+import sys
+import unittest
+
+try:
+    from PyQt4 import QtCore, QtGui, QtTest
+    has_qt = True
+except ImportError:
+    has_qt = False
+
+
+def get_app():
+    """Return existing QApplication or create a new one"""
+    return QtGui.QApplication.instance() or QtGui.QApplication(sys.argv)
+
+
+@unittest.skipUnless(has_qt, "requires PyQt4")
+class TestSafeHTMLParser(unittest.TestCase):
+    """Test the SafeHTMLParser used for message rendering"""
+
+    def test_sanitise(self):
+        """Check that dangerous HTML is stripped"""
+        from bitmessageqt.safehtmlparser import SafeHTMLParser
+        parser = SafeHTMLParser()
+        parser.reset()
+        parser.reset_safe()
+        parser.feed("<b>hello</b> <script/>alert('x')</script> &amp; world")
+        self.assertIn("hello", parser.sanitised)
+        self.assertNotIn("<script", parser.sanitised)
+
+
+@unittest.skipUnless(has_qt, "requires PyQt4")
+class TestMessageView(unittest.TestCase):
+    """Test the MessageView widget in isolation"""
+
+    def setUp(self):
+        self.app = get_app()
+
+    def test_create_messageview(self):
+        """MessageView widget can be instantiated"""
+        from bitmessageqt.messageview import MessageView
+        widget = MessageView(None)
+        self.assertIsNotNone(widget)
+
+    def test_messageview_set_content(self):
+        """MessageView.setContent renders the given text"""
+        from bitmessageqt.messageview import MessageView
+        widget = MessageView(None)
+        widget.setContent("Hello, this is a <b>test</b> message.")
+        self.assertIn("test", widget.toPlainText())
+
+
+@unittest.skipUnless(has_qt, "requires PyQt4")
+class TestAddressValidator(unittest.TestCase):
+    """Test the AddressValidator"""
+
+    def setUp(self):
+        self.app = get_app()
+
+    def test_create_validator(self):
+        """AddressValidator can be instantiated with a buttonBox"""
+        from bitmessageqt.addressvalidator import AddressValidator
+        line_edit = QtGui.QLineEdit()
+        # AddressValidator.setParams() reads the Ok button label on init,
+        # so a real QDialogButtonBox is the simplest way to satisfy that.
+        button_box = QtGui.QDialogButtonBox(QtGui.QDialogButtonBox.Ok)
+        validator = AddressValidator(
+            line_edit, buttonBox=button_box)
+        self.assertIsNotNone(validator)
+        self.assertFalse(validator.isValid)
+
+
+@unittest.skipUnless(has_qt, "requires PyQt4")
+class TestLanguageBox(unittest.TestCase):
+    """Test the language selection combobox"""
+
+    def setUp(self):
+        self.app = get_app()
+
+    def test_create_languagebox(self):
+        """LanguageBox can be instantiated"""
+        from bitmessageqt.languagebox import LanguageBox
+        parent = QtGui.QWidget()
+        combo = LanguageBox(parent)
+        self.assertIsNotNone(combo)
+        self.assertGreater(combo.count(), 0)