We investigated the effects of nifedipine on splanchnic haemodynamics in 13 patients with cirrhosis and portal hypertension, and in 10 control subjects using hepatic venous catheterization and pulsed Doppler ultrasound. There were no significant changes in systemic or splanchnic haemodynamics in control patients. In contrast, systemic vasodilatation, evidenced by significant decreases in mean arterial pressure and systemic vascular resistance, was observed in patients 20 min after sublingual application of 10 mg nifedipine. Moreover, hepatic venous pressure gradient and portal vein blood flow significantly increased after nifedipine administration. There was a significant correlation between the percentage increases in portal vein blood flow and in hepatic venous pressure gradient. However, no correlation was found between the percentage change in cardiac output and that in portal vein blood flow. Thus the increase in portal vein blood flow appears to be related to splanchnic arterial vasodilatation by nifedipine. Consequently, nifedipine has deleterious effects on portal haemodynamics in patients with cirrhosis. As nifedipine may potentially increase the risk of variceal haemorrhage in patients with less advanced varices, this drug should be used with caution in patients with chronic liver disease.