A case of malignant interstitial cell tumor of the testis in man and a review of the literature is presented. This is a rare steroid‐producing tumor; a careful search revealed only 9 published cases. The inadequacy of radiotherapy in management of the disease is dramatically demonstrated. (Periaortic nodes containing metastatic cancer were identified in retroperitoneal areas previously exposed to intensive cobalt therapy.) This lack of radiosensitivity leads to a plea for the use of a radical surgical attack as initial therapy. Illustrations of the comfortable and extensive exposure for a retroperitoneal node dissection using the Nagamatsu approach and technique are presented. Particular interest is aroused by this tumor because its endocrine activity so closely resembles that of cancer of the adrenal cortex. The hormonal disturbances such as gynecomastia and elevated testosterone levels are discussed, as well as the use of OP1‐DDD as a chemotherapeutic agent.