The objective of this study was to determine the patterns of erroneous interpretation of preoperative computed tomography (CT) for detection of peritoneal lesions in advanced ovarian cancer.Between 2007 and 2011, 148 patients with International Federation of Gynecology and Obstetrics stage IIIC-IV ovarian cancer, who underwent multi-detector-row CT before primary cytoreduction, were enrolled. We reviewed the preoperative CT and compared the findings with the surgical findings. For the discrepant cases, false-negative cases were reevaluated after revealing of surgical findings and were categorized as either absence or presence of lesion (missed case). We performed region-based comparisons according to predefined peritoneal lesion locations.Sixty-eight false-negative cases were identified, of which 43 were revealed to be initially missed cases. The most common locations were found to be the small-bowel mesentery (21%), subdiaphragmatic space (19%), and porta hepatis (16%).The missed peritoneal implants commonly resided in the same sites of preoperative imaging criteria that could predict suboptimal primary cytoreduction.