Iterate through the selected items and remove each one
<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="WPF" Height="300" Width="300"> <StackPanel> <ListBox FontSize="16" Height="150" Margin="5" Name="listBox1" SelectionMode="Extended"> <ListBoxItem>List Item 1</ListBoxItem> <ListBoxItem>List Item 2</ListBoxItem> <ListBoxItem>List Item 3</ListBoxItem> </ListBox> <StackPanel HorizontalAlignment="Center" Orientation="Horizontal"> <Label Content="_New item text:" VerticalAlignment="Center" Target="{Binding ElementName=textBox}" /> <TextBox Margin="5" Name="textBox" MinWidth="120" /> </StackPanel> <StackPanel HorizontalAlignment="Center" Orientation="Horizontal"> <Button Click="btnAddListItem_Click" Content="Add Item" IsDefault="True" Margin="5" Name="btnAddListItem" /> <Button Click="btnDeleteListItem_Click" Content="Delete Items" Margin="5" Name="btnDeleteListItem" /> <Button Click="btnSelectAll_Click" Content="Select All" Margin="5" Name="btnSelectAll" /> </StackPanel> </StackPanel> </Window> //File:Window.xaml.cs using System.Windows; using System.Windows.Controls; using System.Windows.Media; namespace WpfApplication1 { public partial class Window1 : Window { public Window1() { InitializeComponent(); } private void btnAddListItem_Click(object sender, RoutedEventArgs e) { if (textBox.Text.Length == 0) { MessageBox.Show("Enter text to add to the list.", Title); } else { ListBoxItem item = new ListBoxItem(); item.Content = textBox.Text; item.IsSelected = true; item.HorizontalAlignment = HorizontalAlignment.Center; item.FontWeight = FontWeights.Bold; item.FontFamily = new FontFamily("Tahoma"); listBox1.Items.Add(item); textBox.Clear(); textBox.Focus(); } } private void btnDeleteListItem_Click(object sender, RoutedEventArgs e) { if (listBox1.SelectedItems.Count == 0) { MessageBox.Show("Select list items to delete.", Title); } else { while (listBox1.SelectedItems.Count > 0) { listBox1.Items.Remove(listBox1.SelectedItems[0]); } } } private void btnSelectAll_Click(object sender, RoutedEventArgs e) { listBox1.SelectAll(); } } }