<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="135" Width="300"> <StackPanel> <Button x:Name="btnThrowUnhandledExceptionFromThread" Click="btnThrowUnhandledExceptionFromThread_Click" Content="Throw Unhandled Exception From a New Thread" Margin="10,5,10,10"/> </StackPanel> </Window> //File:Window.xaml.cs using System; using System.Windows; using System.ComponentModel; namespace WpfApplication1 { public partial class Window1 : Window { public Window1() { InitializeComponent(); } private void btnThrowUnhandledExceptionFromThread_Click(object sender, RoutedEventArgs e) { BackgroundWorker backgroundWorker = new BackgroundWorker(); backgroundWorker.DoWork += delegate { throw new NotImplementedException(); }; backgroundWorker.RunWorkerAsync(); } } }