To evaluate if serum procollagen type III peptide levels reflect the extent of liver fibrosis and hepatic collagen synthesis, we have studied 19 patients with histologically proven alcoholic hepatitis and 9 chronic alcoholics with normal liver histology or minimal steatosis. Serum procollagen peptide type III was measured at the time of liver biopsy, and determination of hepatic prolyl-hydroxylase activity, as an index of collagen synthesis, was performed in all liver samples. Hepatic prolyl-hydroxylase activity and serum procollagen peptide levels were significantly higher in patients with alcoholic hepatitis (959 +/- 115 cpm/mg and 33.2 +/- 5.3 ng/ml, respectively) than in alcoholics from the control group (537 +/- 62 cpm/mg and 10.9 +/- 1.5 ng/ml, respectively) (p less than 0.05 and p less than 0.01, respectively). All patients with alcoholic hepatitis had fibrosis (10 mild and 9 severe). Prolyl-hydroxylase activity and procollagen peptide levels were significantly higher in alcoholic hepatitis patients with severe fibrosis than in those with mild fibrosis (1208 +/- 154 cpm/mg vs. 734 +/- 138 cpm/mg, p less than 0.05 and 49.1 +/- 8.8 ng/ml vs. 20.4 +/- 2.6 ng/ml, p less than 0.01). Furthermore, a close correlation was found between the hepatic prolyl-hydroxylase activity and the serum level of procollagen peptide (r = 0.76, p less than 0.001). We conclude that the serum procollagen peptide level is a good marker of hepatic fibrogenesis in alcoholic hepatitis; thus, its serial measurement could be useful in identifying patients in progress to cirrhosis and in assessing the therapeutic efficiency of antifibrogenic drugs.