Twenty patients with longstanding alcoholism and biopsy-proven alcoholic liver disease presented with marked elevation of serum alkaline phosphatase (in excess of four times the upper limit of normal). None had a past or present history to suggest pancreatitis or biliary tract disease, nor had any of these patients recently taken medication which could be implicated in cholestatic jaundice. Thirteen (65%) of this group either had radiologic or post mortem confirmation of nonobstructed biliary systems. The histologic findings in this group of patients were compared with those of a group of patients with alcoholic liver disease and normal or only mild elevation of serum alkaline phosphatase. Significantly more hepatocellular necrosis (P less than 0.05), alcoholic hyaline (P less than 0.02), and cholestasis (P less than 0.002) were noted in the severely hyperphosphatasemic group. Minimal degrees of steatosis were found in both groups. These data indicate that intrahepatic cholestasis occurs in patients with alcoholic liver disease, and this may often be secondary to alcoholic hepatitis. Overemphasis has previously been given to alcoholic fatty liver as a cause of this syndrome.