I ran into the same thing but couldn't find any suitable answer, at last figured it out on my own. Adding it here, it might help somebody else. Scroll bars appear when child's size increases or it goes out of the bounds of parent. But when you set the Dock Property of child (in this case TreeView) to Fill, the splitter, when resized, changes the size of its child as well. hence no scroll bar will appear. If you must set the Dock property then use AutoScrollMinSize property of parent.