Between February 1982 and February 1986, 30 patients with prostatic cancer received intraoperative radiotherapy (IORT). First 10 cases were treated by the transperineal approach, and after April 1983, 20 cases were done by the retropubic approach. We chose the retropubic approach, because it has advantages over the transperineal approach, which has a risk of rectal damage, lymph-adenectomy can not be performed and the patient can not sit down for a long time after the operation. In the IORT procedure for prostatic cancer by the retropubic approach, a longitudinal lower abdominal incision is made, and pushing down the bladder, the treatment cone is inserted to the prostate. We performed lymph-adenectomy at the same operation, if hard and large lymph-nodes were touched. Of 30 patients, 2 had stage B disease, 10 had stage C and 18 had stage D disease. The overall 5-year survival rate (Kaplan-Meier method) after IORT was 42.6% where as that the 31 cases seen (stage C: 6 cases, stage D: 25 cases) since the Center was founded (October 1975) until the introduction of IORT was 3.2%. Although no definite conclusion can be drawn because all cases received multidisciplinary therapy, IORT appears useful for the treatment of carcinoma of the prostate.