Thirty patients with histologically proven hepatocellular carcinoma were examined ultrasonically. All except two of these cases were reported ultrasonically as having a solid mass. Forty-three per cent of these lesions appeared multiple and 90% had irregular walls or boundaries. Stretching or distortion of the inferior margin of the liver is considered significant and 53% of cases demonstrated this feature. Just over two-thirds (67%) of the lesions were echogenic and under one-third (27%) were mixed lesions with echogenic and transonic areas. These transonic areas are considered to be due to the necrosis within the tumour. Most patients presented late and died within three months. Ninety per cent had clinical hepatomegaly or an epigastric mass. So far the main benefits of ultrasonography have been the recognition or exclusion of treatable disease such as liver abscess, cysts and congestive conditions of the liver, which may also present with unexplained hepatomegaly or epigastric masses. The possibility of a recognisable echo pattern for hepatocellular carcinoma emerged from this study. By conducting selective ultrasonic surveys in endemic areas and by employing the ultrasonic criteria described early diagnosis may be possible. Aspects of management and research may be assisted.