Between March 1986 and March 1989, 65 epithelial ovarian carcinomas were studied by means of real time high resolution ultrasound. The sonographic findings were correlated with FIGO stage, histotype and histological grade. The echostructure was compared with that of a group of 141 benign controls. Moreover, some sonographic patterns, significantly more frequent in the malignant tumors (ascites, irregular borders, peritoneal growths), were identified. The diagnosis of malignancy was as accurate as 90.0%, sensitivity and specificity were 84.7% and 92.3% respectively. Our results, coupled with the low costs involved and the non-invasiveness of the method, thus confirm that ultrasound can still be considered a primary technique in the preoperative assessment of ovarian masses.