To determine whether clinical outcome in patients with acute alcoholic hepatitis is related to the regenerative capability of the liver, liver biopsy specimens from 25 prospectively recruited patients with acute alcoholic hepatitis were studied for hepatic expression of mRNA for two proliferation markers, proliferating cell nuclear antigen and human histone, and for transforming growth factor α (TGFα) and TGFβ₁ and hepatocyte growth factor (HGF), which regulate hepatocyte proliferation. Proliferation markers were detected to varying degrees in 0-80% of hepatocytes and occasionally in sinusoidal cells and bile-duct epithelium in 19 patients (76%). Patients who survived for 6 months had greater expression of proliferation markers than those who did not survive (p<0·01). TGFα was detected in hepatocytes and bile-duct epithelium, whereas TGFβ₁ was detected mainly in sinusoidal cells and was associated with perivenular fibrosis. Patients who survived for 6 months had greater expression of TGFs than non-survivors (p<0·02). HGF was detected in sinusoidal cells in 7 patients and correlated with survival (p<0·01). These data indicate that hepatocyte proliferation, which is possibly related to the pattern of hepatotrophic factor expression, is a good indicator of outcome in acute alcoholic hepatitis.