diff --git a/pyface/i_system_metrics.py b/pyface/i_system_metrics.py
index c86c28245..42382cbdc 100644
--- a/pyface/i_system_metrics.py
+++ b/pyface/i_system_metrics.py
@@ -11,7 +11,7 @@
 """ The interface to system metrics (screen width and height etc). """
 
 
-from traits.api import HasTraits, Int, Interface, Tuple
+from traits.api import HasTraits, Int, Interface, List, Tuple
 
 
 class ISystemMetrics(Interface):
@@ -19,12 +19,15 @@ class ISystemMetrics(Interface):
 
     # 'ISystemMetrics' interface -------------------------------------------
 
-    #: The width of the screen in pixels.
+    #: The width of the main screen in pixels.
     screen_width = Int()
 
-    #: The height of the screen in pixels.
+    #: The height of the main screen in pixels.
     screen_height = Int()
 
+    #: The height and width of each screen in pixels
+    screen_sizes = List(Tuple(Int, Int))
+
     #: Background color of a standard dialog window as a tuple of RGB values
     #: between 0.0 and 1.0.
     # FIXME v3: Why isn't this a traits colour?
diff --git a/pyface/tests/test_system_metrics.py b/pyface/tests/test_system_metrics.py
index fd95d7a9a..2cdc93be0 100644
--- a/pyface/tests/test_system_metrics.py
+++ b/pyface/tests/test_system_metrics.py
@@ -26,6 +26,13 @@ def test_height(self):
         height = self.metrics.screen_height
         self.assertGreaterEqual(height, 0)
 
+    def test_screen_sizes(self):
+        screens = self.metrics.screen_sizes
+        self.assertTrue(all(
+            (isinstance(screen, tuple) and len(screen) == 2)
+            for screen in screens
+        ))
+
     def test_background_color(self):
         color = self.metrics.dialog_background_color
         self.assertIn(len(color), [3, 4])
diff --git a/pyface/ui/qt/system_metrics.py b/pyface/ui/qt/system_metrics.py
index 4f230453a..06ade0135 100644
--- a/pyface/ui/qt/system_metrics.py
+++ b/pyface/ui/qt/system_metrics.py
@@ -11,14 +11,10 @@
 # This software is provided without warranty under the terms of the BSD license.
 # However, when used with the GPL version of PyQt the additional terms described in the PyQt GPL exception also apply
 
-
-from pyface.qt import QtGui, is_qt4
-
-
-from traits.api import HasTraits, Int, Property, provides, Tuple
-
+from traits.api import HasTraits, Int, List, Property, provides, Tuple
 
 from pyface.i_system_metrics import ISystemMetrics, MSystemMetrics
+from pyface.qt import QtGui
 
 
 @provides(ISystemMetrics)
@@ -29,10 +25,17 @@ class SystemMetrics(MSystemMetrics, HasTraits):
 
     # 'ISystemMetrics' interface -------------------------------------------
 
+    #: The width of the main screen in pixels.
     screen_width = Property(Int)
 
+    #: The height of the main screen in pixels.
     screen_height = Property(Int)
 
+    #: The height and width of each screen in pixels
+    screen_sizes = Property(List(Tuple(Int, Int)))
+
+    #: Background color of a standard dialog window as a tuple of RGB values
+    #: between 0.0 and 1.0.
     dialog_background_color = Property(Tuple)
 
     # ------------------------------------------------------------------------
@@ -40,26 +43,28 @@ class SystemMetrics(MSystemMetrics, HasTraits):
     # ------------------------------------------------------------------------
 
     def _get_screen_width(self):
-        # QDesktopWidget.screenGeometry() is deprecated and Qt docs
-        # suggest using screens() instead, but screens in not available in qt
-        # see issue: enthought/pyface#721
-        if not is_qt4:
-            return QtGui.QApplication.instance().screens()[0].availableGeometry().width()
+        screens = self.screen_sizes
+        if len(screens) == 0:
+            return 0
         else:
-            return QtGui.QApplication.instance().desktop().availableGeometry().width()
+            return screens[0][0]
 
     def _get_screen_height(self):
-        # QDesktopWidget.screenGeometry(int screen) is deprecated and Qt docs
-        # suggest using screens() instead, but screens in not available in qt
-        # see issue: enthought/pyface#721
-        if not is_qt4:
-            return (
-                QtGui.QApplication.instance().screens()[0].availableGeometry().height()
-            )
+        screens = self.screen_sizes
+        if len(screens) == 0:
+            return 0
         else:
-            return (
-                QtGui.QApplication.instance().desktop().availableGeometry().height()
+            return screens[0][1]
+
+    def _get_screen_sizes(self):
+        screens = QtGui.QApplication.instance().screens()
+        return [
+            (
+                screen.availableGeometry().width(),
+                screen.availableGeometry().height(),
             )
+            for screen in screens
+        ]
 
     def _get_dialog_background_color(self):
         color = (
diff --git a/pyface/ui/wx/system_metrics.py b/pyface/ui/wx/system_metrics.py
index 16c308f16..78730b445 100644
--- a/pyface/ui/wx/system_metrics.py
+++ b/pyface/ui/wx/system_metrics.py
@@ -15,12 +15,9 @@
 
 import sys
 
-
 import wx
 
-
-from traits.api import HasTraits, Int, Property, provides, Tuple
-
+from traits.api import HasTraits, Int, List, Property, provides, Tuple
 
 from pyface.i_system_metrics import ISystemMetrics, MSystemMetrics
 
@@ -33,10 +30,17 @@ class SystemMetrics(MSystemMetrics, HasTraits):
 
     # 'ISystemMetrics' interface -------------------------------------------
 
+    #: The width of the main screen in pixels.
     screen_width = Property(Int)
 
+    #: The height of the main screen in pixels.
     screen_height = Property(Int)
 
+    #: The height and width of each screen in pixels
+    screen_sizes = Property(List(Tuple(Int, Int)))
+
+    #: Background color of a standard dialog window as a tuple of RGB values
+    #: between 0.0 and 1.0.
     dialog_background_color = Property(Tuple)
 
     # ------------------------------------------------------------------------
@@ -49,6 +53,9 @@ def _get_screen_width(self):
     def _get_screen_height(self):
         return wx.SystemSettings.GetMetric(wx.SYS_SCREEN_Y)
 
+    def _get_screen_sizes(self):
+        return [(self.screen_width, self.screen_height)]
+
     def _get_dialog_background_color(self):
         if sys.platform == "darwin":
             # wx lies.