Abstract Background Prognosis in peritoneal carcinomatosis from gastric cancer has improved with cytoreductive surgery (CS) and hyperthermic intraperitoneal chemotherapy. The aim of this study was to identify predictive factors for incomplete CS. Methods Forty-five patients undergoing laparotomy for gastric cancer with peritoneal carcinomatosis were prospectively included from January 2000 to December 2010. In case of optimal CS, patients (n = 14) received hyperthermic intraperitoneal chemotherapy. Otherwise, the laparotomy was closed or a palliative procedure was performed if necessary. All preoperative data were compared between the 2 groups. Results Ascites (hazard ratio, .09; 95% confidence interval, .010–.48; P = .0103) and nutritional status evaluated by the prognostic nutrition index (hazard ratio, .11; 95% confidence interval, .0019–.54; P = .027) were independent predictive factors for incomplete CS. Conclusions The selection of patients for CS plus hyperthermic intraperitoneal chemotherapy should include the assessment of nutritional status and the detection of an ascites.