Abstract Aims The standard treatment for advanced ovarian cancer consists of cytoreductive surgery associated with a platinum/paclitaxel-based chemotherapy. Nevertheless, there is still the question as to the extent and timing of the surgical debulking. The aim of this study was to evaluate the place of surgery in the therapeutic sequence. Patients and methods We reviewed data from all consecutive patients with stage IIIC and IV epithelial ovarian cancer, operated on at our institution between 1990 and 2005. Patients were divided into 2 groups, according to the position of surgery in the therapeutic sequence. Patients in group 1 received initial debulking surgery. Group 2 consisted of patients having received their first debulking after initial chemotherapy. Results Two hundred and three patients were identified and frequently underwent aggressive surgery, in particular, digestive surgery with bowel resections. Perioperative mortality and morbidity rates were low (2% and 14%, respectively) and there was no difference between the groups. Overall survival in group 1 for patients with complete cytoreduction (residual disease (RD) = 0), optimal surgery (RD < 1 cm) or sub-optimal surgery (RD > 1 cm) was 50%, 30% and 14%, respectively. In group 2, overall survival following complete surgery was 30%, and no long-term survival was observed when surgery was not complete at the time of interval surgery. Survival was worse for patients who had received more than 4 cycles of neoadjuvant chemotherapy. Conclusion This study confirms the importance of surgery in the prognosis of advanced ovarian cancer. Only the patient subgroup that underwent complete initial or interval surgery was associated with a prolonged remission. Optimal surgery with a controlled morbidity can be achieved in many cases, even if bowel resection is needed, at the time of primary debulking. In the interval cytoreductive surgery subgroup, the response to initial chemotherapy and surgery was found to be essential for prognosis.