The acute effects of nifedipine, 10 mg administered sublingually, were studied in 10 patients with alcoholic cirrhosis. Nifedipine significantly increased cardiac output and reduced systemic vascular resistance. Nifedipine also increased the hepatic venous pressure gradient by 15% (P less than 0.01). Hepatic blood flow and azygos blood flow did not change significantly. It is suggested that nifedipine increases portal pressure and thus may be deleterious to patients with portal hypertension.