A second-look operation was performed on 171 patients with stage III and IV epithelial ovarian carcinoma who had responded to primary surgery and chemotherapy. 19% of the 89 patients who appeared clinically to be free of disease had microscopic recurrences and 23% had macroscopic residual disease at a second-look surgery. Only patients with well differentiated tumors and a small residual tumor mass at first operation had a good prognosis after a second-look operation even without further chemotherapy. Median survival after secondary debulking was 15 to 17 months and was independet in the radicality of the second-look procedure. Outside of clinical trials secondlook laparotomy should therefore only be performed as a diagnostic procedure in patients with well differentiated tumors who are left with a small residual tumor mass at the time of the first operation. In these patients chemotherapy can be discontinued after a negative second-look surgery. In all other patients with advanced epithelial ovarian carcinoma second-look-operation seems unnecessary. Second-look surgery might however still be of importance in the context of prospective randomized clinical trials.