Remove height and width from stackpanel..rest is working fine here.
<ScrollViewer HorizontalAlignment="Left" Background="Green" Height="299" Margin="592,120,0,0" VerticalAlignment="Top" Width="188" VerticalScrollBarVisibility="Auto">
<StackPanel x:Name="stackPanelVistaProfiloTessera" Background="RoyalBlue" >
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
<Label Height="30" Width="100" Margin="5">label1</Label>
</StackPanel>
</ScrollViewer>
Output look like this.
and you can set margin to stackpanel if you are using height and width for design purpose.