To describe the sonographic morphological features of gestational choriocarcinoma.Retrospective evaluation of 13 cases of gestational choriocarcinoma diagnosed by clinical and laboratory (BHCG) criteria in all cases and confirmed by histological data in 8 cases.The tumor presented multiple features (nodular, submucosal, macrocystic, multicystic, compact and microcystic) often with involvement of surrounding tissues. All cases showed myometrial involvement. The size of the ovaries was normal with small corpus luteum cysts noted in only 5 cases. In 2 cases, ultrasound modified the clinical staging.Sonographic features of gestational choriocarcinoma are variable, and may mimic other diseases of the endometrium or myometrium. The involvement of multiple layers of the uterus suggests a malignant disease.