Postoperative residual tumor is the major prognostic factor in ovarian cancer. The feasibility of complete cytoreductive surgery is assessed by laparoscopy. Our goal was to develop a predictive score prior to laparoscopy to evaluate the feasibility of complete cytoreductive surgery in patients with epithelial ovarian cancer. We developed a score to predict incomplete cytoreductive surgery by performing multiple logistic regressions after bootstrap procedures on data from a retrospective cohort of 247 patients with advanced ovarian cancer. This score was validated on a different population of 45 patients with ovarian cancer. Four criteria were independently associated with incomplete cytoreduction, confirmed by surgery: BMI ≥ 30 kg/m2 (adjusted odds ratio aOR, 3.07; 95% confidence interval 95% CI, 1.0-9.6), CA125 > 100 IU/L (aOR, 3.99; 95% CI, 1.6-10.1), diaphragmatic and/or omental carcinomatosis by CT-Scan (aOR, 5.82; 95% CI, 2.6-13.1), and positive parenchymal metastases by PET/CT (aOR, 3.59; 95% CI, 1.0-12.8). The 100-point score was based on these criteria. The area-under-the-curve of the score was 0.79 (95% CI, 0.73-0.86). In the validation group, no patient ranked in the high-risk group of incomplete cytoreductive surgery had a complete upfront cytoreductive surgery (95% CI 0-16). Three of 29 patients for whom primary complete cytoreduction was not possible were classified in the group at low risk of incomplete cytoreductive surgery (12%; 95% CI 4-27). This pre-operative score may be useful for distinguishing which patients may have complete cytoreductive surgery from those who will receive neoadjuvant chemotherapy, while avoiding unnecessary laparoscopy.