In an aim to evaluate the diagnostic efficacy of preoperative abdominal-pelvic CT for the prediction of suboptimal cytoreduction of epithelial ovarian carcinoma (EOC) at primary surgery, CT scans of 48 patients who underwent primary surgery for EOC were retrospectively analyzed. The presence of at least one of the following CT findings: multiple implants > 1 cm in maximum diameter in the mesenteria of the small or large intestines, porta hepatis or intersegmental fissure or on the hepatic surface, diaphragmatic peritoneum, gastrohepatic or gastrosplenic ligaments or the extension of tumor infiltration > 2 cm on the omentum towards the spleen or stomach or the intestines encased by the tumor > 2 cm, diffuse peritoneal thickening or invasion of the lateral pelvic wall > 1 cm or multiple lymph nodes > 1 cm at the cardiophrenic and suprarenal levels were accepted as the critical markers for predicting suboptimal cytoreduction. Suboptimal surgery, defined as leaving a residual tumor mass > 1 cm, was determined in 18 (37.5%) patients. CT predicted suboptimal cytoreduction with 83.3% (15/18) sensitivity, 90% (27/30) specificity and 87.5% (42/48) accuracy. PPV and NPV values were 83.3% (15/18) and 90% (27/30), respectively. These results suggested that preoperative CT could successfully predict suboptimal surgery in patients with EOC.