[en] To assess the value of CT for the differential diagnosis of malignant ovarian tumors. We reviewed CT scans of 31 patients with surgically confirmed 46 malignant ovarian tumors. (29 epithelial tumors, 9 Krukenberg tumors, 6 germ cell tumors, and 2 sex cord-stromal tumors.) CT scans were evaluated for the mass (bilaterality, size, internal component, and margin), peritoneal spread pattern, ascites, invasion of adjacent organ, and lymphadenopathy. Bilateral masses were seen in epithelial or Krukenberg tumor in 61.1%(11/18) and 80%(4/5) respectively. Epithelial tumors showed predominantly cystic mass(37.9%, 11/29), irregular margin(82.8%, 24/29) of mass, and accompanying peritoneal and omental spread (66.7%, 12/18), while Krukenberg tumor showed predominantly solid mass(55.5%, 5/9), smooth margin of mass(100%, 5/5), and no peritoneal and omental spread. All cases with germ cell tumor or sex cord-stromal tumor showed unilateral mass. Relatively young aged, unilateral solid (66.7%, 4/6) tumors were germ cell tumor. Of these cases, septa within solid portion of mass were prominent in all dysgerminoma. (3/3) CT may be a valuable tool for the differential diagnosis of malignant ovarian tumors