 <p>Use <code>JFXPanel</code>:</p> <pre><code> public class Test { private static void initAndShowGUI() { // This method is invoked on Swing thread JFrame frame = new JFrame("FX"); final JFXPanel fxPanel = new JFXPanel(); frame.add(fxPanel); frame.setVisible(true); Platform.runLater(new Runnable() { @Override public void run() { initFX(fxPanel); } }); } private static void initFX(JFXPanel fxPanel) { // This method is invoked on JavaFX thread Scene scene = createScene(); fxPanel.setScene(scene); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { initAndShowGUI(); } }); } } </code></pre> <p>where method <code>createScene()</code> is <code>start(final Stage stage)</code> from your code. Just instead of putting scene to stage you return it.</p>