From January to December 1991, the portal venous system was evaluated by Doppler ultrasonography in 72 patients with liver cirrhosis. The objectives of this study were to evaluate the prevalence of spontaneous reversal of blood flow in the portal vein and to assess the relationship between Doppler ultrasound investigation and clinical, biochemical, endoscopic (70 patients), and endosonographic (44 patients) features. Reversed flow was quite frequent (alternating: 17%, permanent: 22%) and its prevalence did not differ in relation to age, sex, serum gammaglobulin concentration and Child-Pugh class. In patients with reversed portal venous flow, the prevalence of hepatic encephalopathy was higher (39% vs 13.5%, P < 0.05), but the prevalence of esophageal or gastric varices was not related to that pattern. Endosonography detected gastric wall abnormalities in a higher proportion of patients with reversed portal flow than in patients without it (P < 0.05). This study suggests that reversal of flow in the portal vein could play a role in the development of the gastric wall abnormalities in liver cirrhosis, which are detected by endosonography but not by endoscopy.