RadTreeView with virtualization turned on, defines HierarchicalDataTemplates for its items. In the template, the root panel is 32 pixels (or higher than the default TreeViewItemHeight - 24 px in OfficeBlackTheme). Scrolling the treeview, then maximizing the wpf window results in misplaced / incorrect height of treeviewitems. Possible workaround: Set the MinHeight property of RadTreeViewItem so that all its header content fits. Then set the item's VerticalConentAlignment to Stretch <Style TargetType="telerik:RadTreeViewItem"> <Setter Property="MinHeight" Value="48" /> <Setter Property="VerticalContentAlignment" Value="Stretch" /> </Style> The XAML team has recently reviewed this issue and will not be addressing it as at this time the team is focusing on the bugs impacting the highest number of developers. If you have encountered this issue and it is blocking for your work please contact us through the support ticketing system with details on your setup and a reference to this item.