BACKGROUND: Secondary surgical cytoreduction in women with platinum-sensitive, recurrent epithelial ovarian, primary peritoneal, or fallopian-tube ("ovarian") cancer is widely practiced but has not been evaluated in phase 3 investigation. METHODS: We randomly assigned patients with recurrent ovarian cancer who had received one previous therapy, had an interval during which no platinum-based chemotherapy was used (platinum-free interval) of 6 months or more, and had investigator-determined resectable disease (to no macroscopic residual disease) to undergo secondary surgical cytoreduction and then receive platinum-based chemotherapy or to receive platinum-based chemotherapy alone. Adjuvant chemotherapy (paclitaxel-carboplatin or gemcitabine-carboplatin) and use of bevacizumab were at the discretion of the investigator. The primary end point was overall survival. RESULTS: A total of 485 patients underwent randomization, 240 to secondary cytoreduction before chemotherapy and 245 to chemotherapy alone. The median follow-up was 48.1 months. Complete gross resection was achieved in 67% of the patients assigned to surgery who underwent the procedure. Platinum-based chemotherapy with bevacizumab followed by bevacizumab maintenance was administered to 84% of the patients overall and was equally distributed between the two groups. The hazard ratio for death (surgery vs. no surgery) was 1.29 (95% confidence interval [CI], 0.97 to 1.72; P = 0.08), which corresponded to a median overall survival of 50.6 months and 64.7 months, respectively. Adjustment for platinum-free interval and chemotherapy choice did not alter the effect. The hazard ratio for disease progression or death (surgery vs. no surgery) was 0.82 (95% CI, 0.66 to 1.01; median progression-free survival, 18.9 months and 16.2 months, respectively). Surgical morbidity at 30 days was 9%; 1 patient (0.4%) died from postoperative complications. Patient-reported quality of life decreased significantly after surgery but did not differ significantly between the two groups after recovery. CONCLUSIONS: In this trial involving patients with platinum-sensitive, recurrent ovarian cancer, secondary surgical cytoreduction followed by chemotherapy did not result in longer overall survival than chemotherapy alone. (Funded by the National Cancer Institute and others; GOG-0213 ClinicalTrials.gov number, NCT00565851.).