Advanced epithelial ovarian cancer (OC) patients often present with malnutrition; however, the ideal nutritional evaluation tool is unclear. We aimed to evaluate the role of preoperative albumin, Prognostic Nutritional Index [PNI], neutrophil-to-lymphocyte ratio [NLR], and platelet-to-lymphocyte ratio [PLR] as independent predictors of severe postoperative complications and 90-day mortality in OC patients who underwent primary cytoreductive surgery to identify the ideal tool.