Supernumerary kidney is one of the rarest congenital anomalies of the genito-urinary tract. Around 100 cases have been reported in the literature so far. Even rare is the fusion of a supernumerary kidney. The supernumerary kidney has its own blood supply, collecting system and a capsule. We report the case of a 33 year old male with vague pain in the pelvis who was found to have a horseshoe kidney with a fused supernumerary kidney as the isthmus.