Even though ultrasonography is a primary tool for evaluation of gynecological pelvic mass, CT can be helpfulwhen ultrasonography is suboptimal either because of abundant intestinal gas or marked obesity. Authorsexperienced 3 cases of hydatidiform mole demonstrated by CT. The findings of hydatidiform mole are enlargement ofuterus, low density in the uterine cavity, irregular soft tissue mass with small multiple cysts, and strongcontrast enhancement of the soft tissue mass within the uterine cavity. CT can be a useful diagnostic tool fordifferentiation of hydatidiform mole from choriocarcioma because of good visualization of uterine wall and pelvicstructures.