<style TargetType="{x:Type TabControl}">
<setter Property="Template">
<setter.Value>
<controlTemplate TargetType="{x:Type TabControl}">
<grid>
<grid.RowDefinitions>
<rowDefinition Height="Auto"/>
<rowDefinition Height="*"/>
</grid.RowDefinitions>
<tabPanel Grid.Row="0" IsItemsHost="True" />
<scrollViewer Grid.Row="1"
VerticalScrollBarVisibility="Auto"
Margin="5,5,5,5"
Background="White">
<contentPresenter ContentSource="SelectedContent" />
</scrollViewer>
</grid>
</controlTemplate>
</setter.Value>
</setter>
</style>
A very good example of how to style a WPF TabControl.
From Brandon Cannaday at Switch on the code.
I use this Style to surround each TabItem Content with a ScrollViewer:


