Use Tooltip
<Window x:Class="Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Use Tooltip" Height="138" Width="300"> <Grid> <Button Height="23" HorizontalAlignment="Left" Margin="10,10,0,0" Name="Button1" VerticalAlignment="Top" Width="75" ToolTip="This is a simple tooltip">Button</Button> <Button Height="23" HorizontalAlignment="Left" Margin="10,43,0,0" Name="Button2" VerticalAlignment="Top" Width="75" Content="Button"> <Button.ToolTip> <ToolTip> <StackPanel> <TextBlock HorizontalAlignment="Left">This is a much more</TextBlock> <TextBlock HorizontalAlignment="Center"> <Italic> <Bold>elaborate</Bold> </Italic> </TextBlock> <TextBlock HorizontalAlignment="Right">tooltip!</TextBlock> </StackPanel> </ToolTip> </Button.ToolTip> </Button> </Grid> </Window>