PURPOSE: On the basis of CT findings, to differentiate between solid ovarian tumor and uterine subserosalmyoma. MATERIALS AND METHODS: In eight surgically proven cases of solid ovarian tumor and in ten uterinesubserosal myoma patients, contrast-enhanced CT images were obtained. Two genitourinary radiologists reviewed thefindings with regard to degree of enhancement of the mass as compared with enhancement of uterine myometrium,thickening of round ligaments, visualization of normal ovaries, contour of the mass, and the presence of ascitesin the pelvic cavity. RESULTS: Six of eight ovarian tumors but only two of ten uterine myomas were less enhancedthan normal uterine myometrium (p <0.05). Pelvic ascites were seen in six of eight ovarian tumors, but in only oneof ten uterine myomas (p<0.05). Three of 16 ovaries in ovarian tumor patients, but 12 of 20 ovaries in uterinemyoma patients, were normal (p<0.05). Six of 16 round ligaments of the uterus in ovarian tumor patients, were thichened but 11 of 20 round ligaments in uterine myoma patients, were thickened (p>0.05). The contour of themass was lobulated in two of eight ovarian tumor patients, but in five of ten uterine myoma patients (p>0.05). CONCLUSION: CT findings suggestive of solid ovarian tumor were less contrast enhancement of the mass than ofnormal uterine myometrium, pelvic ascites, and nonvisualization of normal ovary.