how can I remove the top border on UIToolBar

toolbar1.clipsToBounds = YES;  

Worked for me incase someone is still trying with Navigational bar

Correct answer is the one by totalitarian...FYI. https://stackoverflow.com/a/14448645/627299

My response is still below for reference.

---

Here's what I did with my WHITE background toolbar...

whiteToolBar.layer.borderWidth = 1;
whiteToolBar.layer.borderColor = [[UIColor whiteColor] CGColor];    

Perhaps you could do the same thing with your color instead.

You can do like this:

self.navigationController.toolbar.clipsToBounds = YES;