Ulex europaeus 1 lectin (UEA1) has previously been shown to bind to hepatic sinusoidal endothelium in cirrhotic liver. This study was undertaken to determine the relationship between UEA1 sinusoidal binding and hepatic venous pressure gradient in patients with portal hypertension. Twenty one liver specimens (including 18 from patients with alcoholic cirrhosis) biopsied within an interval of 1 month from the hepatic venous pressure study were examined for UEA1 binding. The consistent staining pattern of normal liver controls formed the basis for the criteria of positivity and grading system. Seventeen cases (81%) were positive, but the staining intensity or extent showed no strong correlation with the hepatic venous pressure gradient; however, three of the four negative cases were in the low pressure range which is rarely associated with variceal bleeding. We conclude that UEA1 is a useful marker for significant sinusoidal alterations in portal hypertension and a helpful adjunct in the histological diagnosis of cirrhosis.