ABSTRACT: To determine the prognostic importance of pleural effusions on preoperative computed tomographic (CT) images in patients with advanced epithelial ovarian cancer.The institutional review board waived informed consent for this HIPAA-compliant study of 203 patients with International Federation of Obstetrics and Gynecology stage III (n = 172) or IV (n = 31) epithelial ovarian cancer who underwent CT before primary cytoreductive surgery between 1997 and 2004 (mean age, 61 years; range, 37-96 years). Two radiologists retrospectively evaluated chest and/or abdominal CT images for pleural malignancy and the presence, size, and laterality of pleural effusions. To evaluate survival, Kaplan-Meier methods were used, with log-rank P values for comparisons. Multivariate analyses were conducted by using Cox proportional hazards regression. κ Statistics were calculated for interreader agreement.Median survival was 50 months (95% confidence interval [CI]: 45, 55 months) for patients with stage III disease and 41 months (95% CI: 27, 58 months) for patients with stage IV disease. Readers 1 and 2 found pleural effusions in 40 and 41 stage III and 20 and 21 stage IV patients, respectively. At multivariate analysis, after controlling for stage, age at surgery, preoperative serum CA-125 level, debulking status, and ascites, moderate-to-large pleural effusion on CT images was significantly associated with worse overall survival (reader 1: hazard ratio = 2.27 [95% CI: 1.31, 3.92], P < .01; reader 2: hazard ratio = 2.25 [95% CI: 1.26, 4.01], P = .02). Preoperative CA-125 level, debulking status, and ascites were also significant survival predictors (P ≤ .03 for all for both readers). Readers agreed substantially in distinguishing small from moderate-to-large effusions (κ = 0.764).Moderate-to-large pleural effusion on preoperative CT images in patients with stage III or IV epithelial ovarian cancer was independently associated with poorer overall survival after controlling for age, preoperative CA-125 level, surgical stage, ascites, and cytoreductive status.