I think your problem is probably the fact that a text view, when dragged into a window in Interface Builder, is actually a scroll view with a text view as its document view. So, to move it around, you'll want to change the scroll view's frame, since changing the text view's frame will simply change its size within the scroll view. You can get the scroll view that contains the text view by using the enclosingScrollView method (declared on NSView)>