To evaluate the necessity of an excretory urogram before prostatectomy the records of 557 patients admitted to 3 community hospitals in 1977 and 1978 for urinary obstruction were reviewed. Of the entire series 27 per cent revealed urographic abnormalities and 72 significant lesions of the upper urinary tract were noted. An operation other than prostatectomy was necessary in 14 cases. Abnormalities involving the bladder were detected in 29 cases. We conclude that excretory urography remains a sound principle of proper urologic care.