Techniques for removing or identifying overlapping fragments in a fragment stream after z-culling are disclosed. The techniques include maintaining a first-in-first-out buffer that stores post-z-cull fragments. Each time a new fragment is received at the buffer, the screen position of the fragment is checked against all other fragments in the buffer. If the screen position of the fragment matches the screen position of a fragment in the buffer, then the fragment in the buffer is removed or marked as overlapping. If the screen position of the fragment does not match the screen position of any fragment in the buffer, then no modification is performed to fragments already in the buffer. In either case, he fragment is added to the buffer. The contents of the buffer are transmitted to the pixel shader for pixel shading at a later time.