The effect of oral testosterone treatment (200 mg tid) on liver morphology was examined in a double-blind, placebo controlled study including men with alcoholic cirrhosis (n = 126). Liver biopsies obtained before randomization showed micronodular cirrhosis in 119 patients (94%), alcoholic hepatitis in 64 (51%), and fatty liver in 104 (83%). These and other morphological findings did not differ significantly in the patients randomized to testosterone (n = 76) and to placebo (n = 50) (skewed randomization 3:2). Follow-up liver specimens (biopsies or autopsies) obtained after a median treatment duration of 30 months demonstrated a significant (p less than 0.01) increase in the prevalence of macronodular cirrhosis (from 6 to 51%) and a significant (p less than 0.01) decrease in the prevalence of alcoholic hepatitis (to 21%) and of fatty liver (to 52%). Testosterone treatment did not significantly influence the prevalence of these changes. Further, testosterone treatment had no significant effect on the prevalence of other morphological changes, including vascular and malignant changes. However, in the testosterone-treated group one patient developed diffuse sinusoidal dilation and one patient showed Budd-Chiari's syndrome. The degree of fatty liver and of alcoholic hepatitis in follow-up liver specimens were significantly (p less than 0.002) higher among patients who consumed ethanol during follow-up than in patients who abstained (76 versus 22% and 30 versus 6%). In conclusion, this study does not establish any indication or any contraindication in terms of hepatic histopathology with the possible exception of hepatic venous thrombosis for the use of oral testosterone treatment in men with alcoholic cirrhosis.