Anomalies or congenital malformations of the kidney and ureter are of frequent occurrence, and abundant reports are available concerning their types and varieties. That such developmental anomalies often give rise to clinical symptoms is perhaps less generally recognized. The symptoms of disease so caused are frequently obscure and misleading, while the results of routine physical examination may be quite without significant positive value. Examination of the urine often does not supply data pointing to the urinary tract as the source of the patient's complaints. Thus, one finds that there is frequent recourse to an "exploratory laparotomy," with removal of a normal appendix, gallbladder or salpinx, while the underlying pathology escapes notice. It is our belief that many such cases presenting obscure abdominal symptoms, in which the usual methods of diagnosis have failed to demonstrate significant pathologic processes, will be clarified if these renal anomalies are kept in mind and pyelography