The diagnosis of ovarian tumor has been mainly dependent on manual pelvic examination and ultrasonography. But in case of malignant ovarian tumor, CT has more advantage over ultrasonogrpahy in assessing anatomic details, relationships to bowel loops, precise extents of tumors and follow-up examinations after surgery. Authors analyzed CT features of 46 cases of pathologically proven ovarian tumors for recent 4 years at Keimyung Univeristy Dongsan Hospital. The results were as follows : 1. The most common tumor was serous cystadenocarcinoma (9case : 20%), followed by metatases(8cases : 17%), mucinous cystadenocarcinoma(7cases : 15%)m mucinous cystadenocarcinoma(5 cases ; 11%), teratoma (5 cases : 115), lymphoma(3 cases : 7%) and dysgerminoma (2 cases : 4%). 2. The ovarian tumors were variable in size from 2.5 cm to 33 cm in diameter. Most of the solid tumors were smaller than 10 cm in diameter and most of the cystic tumors . mucinous cystadenomas were the largest tumors. 3. Unil teral tumors(left 19, right 13 cases) were more common than bilateral tumors(12 cases). Bilateral tumors were seen in serous and mucinous cystadenocarcinoma, metastases and lymphoma. 4. CT features of mucinous cystadenomas were smooth margins and thin wall of the tumor masses and multiloculated cysts with internal septa in all 7 cases. 5. In contrast, CT demontration of bilaterality, irregular margin, thick wall, enhancing solid lesion, septal irregulatity, adhesion to adjacent structures. peritoneal/omental implantation , ascitesa and hydronephrosis were signs suggesting malignancy. CT features of the serous cystadenocarcinoma were mostly solid to mixed nature(83%), irregular margin975%), enhancing solid lesion(67%), papillary growth(75%), inthernal septa (58%), multilocularity(58%) and calcification (25%) indescending order of frequency. 6. On CT, mucinous cystadenocarcinoma were irregrular-marginated, thick-walled, cystic tumors with enhancing solid lesion, septal irregularity and s gns of metastasiss, altohough there were some cases having similar feature of benign. 7. Among the extrapelvic CT finding of malignant epithelial ovarian tumor, peritoneal/omental implants(11 cases : 79%) and ascites(10 cases : 71%) were the most ocmmon, and indistinct uterus (6 cases : 43%) bowel adhesion(5 cases : 36%) and pseudomyxoma peritonei (2 cases) were descending order of frequency. 8. CT features of teratoma were diagnostic having at least three more of different tissue densities among fat, water, soft tissue and calcific densities. Also there were thick wall (4 cases) and fat-fluid level(l cases). 9. In 8 cases of ovarian metastases, there were solid type tumor smaller than 10 cm in 4 cases and huge cystic in 2 cases. The site of primary cancer were stomach in 4 cases, colon, cervix, endometrium and unknown in each one cases. 10. In 3 cases of malignant lymphoma, the CT features were solid in appearance, smaller than 10 cm and accompanied by lymhadenopathy in all cases.