Hepatic venocclusive disease is a serious complication associated with chemotherapy and radiation used in bone marrow transplantation patients. In the past, liver biopsy has been the only reliable means of diagnosing venocclusive disease. Biopsy in such patients may be dangerous or impossible because of severe coagulopathies. The purpose of our study was to evaluate duplex Doppler sonography in diagnosing hepatic venocclusive disease. We measured the blood velocity and flow in the portal vein, hepatic vein, and inferior vena cava of six patients who were histologically proved to have developed hepatic venocclusive disease after bone marrow transplantation. There were three men and three women with a mean age of 32 years (range, 21-44 years). Examination with Doppler sonography suggested the diagnosis a mean of 41 days (range, 11-62 days) after transplantation. In three patients, the diagnosis was suggested by reversed or "to and fro" flow in the portal vein. In the other three patients, the diagnosis was suggested by a decreased flow in the portal vein. One of these patients with decreased flow had subclinical hepatic venocclusive disease. In this patient, it was not the absolute level of flow but the decrease from a baseline established before ablative therapy that suggested the diagnosis. The amplitude of pulsatility in the hepatic veins appeared to decrease with the onset of venocclusive disease. In the hepatic veins and inferior vena cava, flow toward the heart was maintained. Our findings suggest that duplex Doppler sonography may be useful in detection of hepatic venocclusive disease. We speculate that, with wider experience, Doppler sonographic detection of decreased or reversed flow in the portal vein, in the proper clinical setting, may provide a noninvasive means of reliably diagnosing hepatic venocclusive disease in patients too ill to undergo liver biopsy.