RadioButton with GroupName
<UserControl x:Class='SilverlightApplication3.MainPage' xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' xmlns:d='http://schemas.microsoft.com/expression/blend/2008' xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006' mc:Ignorable='d' d:DesignWidth='640' d:DesignHeight='480'> <Grid x:Name="LayoutRoot" Background="White"> <StackPanel Orientation="Vertical" Background="Yellow"> <RadioButton Content="Option 1" IsChecked="true" GroupName="G1" ></RadioButton> <RadioButton Content="Option 2" GroupName="G1" /> <RadioButton Content="Option 3" GroupName="G2" /> <RadioButton Content="Option 4" GroupName="G2" /> <RadioButton Content="Option 5" GroupName="G3" IsChecked="true" /> <RadioButton Content="Option 6" GroupName="G3" /> <RadioButton Content="Option 7" GroupName="G3" /> <RadioButton Content="Option 8" GroupName="G3" /> </StackPanel> </Grid> </UserControl>