OBJECTIVES: Complete surgery with no macroscopic residual disease (RD) at primary (PDS) or interval debulking surgery (IDS) is the main objective of surgery in advanced epithelial ovarian cancer (EOC). The aim of this work was to evaluate the impact on survival of the number of neoadjuvant chemotherapy (NAC) cycles before IDS in EOC patients. METHODS: Data from EOC patients (stages IIIC-IV), operated on between 1995 and 2010 were consecutively recorded. NAC/IDS patients were analyzed according to the number of preoperative cycles (\textless4=group B1; \textgreater4=group B2) and compared with patients receiving PDS (group A). Patients with complete resection were specifically analyzed. RESULTS: 367 patients were analyzed, 220 received PDS and 147 had IDS/NAC. In group B, 37 patients received more than 4 NAC cycles (group B2). Group B2 patients presented more frequently stage IV disease at diagnosis (p\textless0.01) compared to groups A and B1. The rate of complete cytoreduction was higher in group B (p\textless0.001). Patients with no RD after IDS and who had received more than 4 NAC cycles had poor survival (p\textless0.001) despite complete removal of their tumor (relative risk of death after multivariate analysis of 3 (p\textless0.001)) with an independent impact from disease stage and WHO performance status. CONCLUSIONS: Patients with advanced EOC receiving complete IDS after more than 4cycles of NAC have poor prognosis. Despite worse prognostic factors observed in this group of patients, our study reinforces the concept of early and complete removal of all macroscopic tumors in the therapeutic sequence of EOC.