Crossed renal ectopia is a relatively unusual congenital anomaly. Bilateral crossed renal ectopia is considered the rarest form of this anomaly. A 19-year-old girl with intermittent flank pain was admitted to our department. Various clinical and laboratory examinations were carried out. Excretory urography showed a normal upper urinary tract anatomy, whereas the distal ends of the ureters crossed each other in the pelvis, which suggested bilateral crossed renal ectopia. © 1996 S. Karger AG, Basel.