From February 1977 to February 1981 we treated 55 patients with ovarian cancer (45 stage III and 10 stage IV) with simultaneous radio-chemotherapy; 34 of these patients underwent a therapeutic second-look operation. The overall response rate was 94%, comprising 63% complete and 31% partial remissions. In the group with residual tumours exceeding 2 cm in diameter after primary operation 52% complete remissions were observed. In the stage III group there were 74% complete and 26% partial remissions. Cytoreductive surgery to less than 2 cm was achieved by means of an early second-look operation in 74% of these cases. These patients have as good a prognosis as those with an equivalent residual tumour after primary resection. Unlike the cases with tumour spread to the retroperitoneal area, macroscopic tumour spread to the surface of the liver or diaphragm indicated a worse prognosis. The survival time of patients who prove to be tumour-free at the time of the diagnostic operation is significantly longer than of those with residual tumours. Neither the age of the patients nor the histological findings after primary operation have any significant influence on survival time. Late intestinal complications made us change the therapeutic strategy employed since March 1981 to sequential radio-chemotherapy. Possible cure for stage III patients can be achieved only by way of interdisciplinary cooperation. In stage IV patients the prognosis is so bad that local therapy is possible only in selected cases.