The anomaly horseshoe kidney, apart altogether from accompanying renal pathologic change, presents a clear-cut and definite clinical problem. It is the problem of what may be called horseshoe kidney disease as distinct from disease of the horseshoe kidney. The literature abounds in reports of the occurrence of the anomaly horseshoe kidney and in descriptions of its morphology and autogenesis. There is an abundance of clinical reports dealing with disease of the horseshoe kidney. They recount occurrence of all the ordinary renal lesions such as hydronephrosis, pyonephrosis, stone, tuberculosis and neoplasm, found in association with this extraordinary form of kidney. Some of the reports speculate concerning the anomaly as an etiologic factor in occurrence of the associated lesion. In all but a few reports, to be mentioned in detail later, the anomaly has not been held directly responsible for the symptoms present and no attempt has been made to eliminate it