There are two things you can do to affect the size of the image drawn in an NSImageView. If you call setScalesWhenResized: on your NSImage object and pass in YES, you can then call setSize: on the NSImage and it will automatically scale the image to the new size. You can also call setImageScaling: on the NSImageView to tell it how to draw the image within its frame. You can have it not change the size at all, draw the image to fill its entire frame, or size it proportionally to fit one dimension of the frame but maintain the same height/width ratio.