Background Epithelial ovarian cancer is usually diagnosed at advanced stages. To choose the best therapeutic approach, an accurate assessment of the tumor spread is crucial. This study aimed to determine whether numeric scoring, the amount of ascites, and the presence of cardiophrenic nodes (CPLNs) visualized by computed tomography (CT), can predict the tumor extent and improve the outcome of AOC upfront surgery. Methods This single center retrospective analysis of 194 patients diagnosed with AOC included 119 patients treated with upfront surgery at the Skåne University Hospital, Lund, Sweden, from January 2016 to December 2018. CT based peritoneal cancer index (PCI) scores, enlarged cardiophrenic lymph nodes (CPLNs), and the amount of ascites were correlated to the surgical PCI (S-PCI) and the completeness of the cytoreductive surgery.The patients were grouped according to the residual disease (RD) and the overall survival (OS) rates for the three groups were determined using Kaplan-Meier curves. Linear regression and the interclass correlation (ICC) analyses were used to determine the relationship between CT-PCI and S-PCI. Results The survival rate was significantly higher in patients with no macroscopic residual disease compared those with residual disease <10 mm (p<0.03) or residual disease ≥10 mm (p<0.005). S-PCI and large ascites volumes were correlated with the risk of suboptimal residual disease (for ascites > 1000 ml, OR 5.5626 (1.665-19.007) p<0.019; for S-PCI, OR 1.24 (1.141-1.348), p<0.001). CT-PCI, CA-125 level and CPLN were not predictive of the cytoreductive surgery results in the adjusted data to days from CT to operation and for ascites. CT-PCI correlated well to S-PCI ((95%) CI: 0.397 (0.252-0.541) p<0.001). Conclusions CT is a reliable tool for assessing the extent of the disease in AOC, but it has limitations in predicting surgical outcome. This study was unable to show an association between the CT-PCI and surgical outcome when the data were adjusted and ascites, CA-125 level, days between the CT examination to surgery and CPLN. Ascites volumes exceeding 1000 ml increased the risk of residual disease and thereby worse outcome. That certain areas (e.g., small bowel region) are particularly critical when evaluating surgical outcome using preoperative CT-PCI warrants further investigation.