Serum concentrations of testosterone, dihydrotestosterone, estradiol-17β (E2), and gonadotrophins were studied in 13 male patients with hepatic cirrhosis. The mean serum total and unbound testosterone concentrations were significantly lower in the cirrhotic patients than in normal men. Serum dihydrotestosterone levels were also subnormal in five of six patients studied. On the other hand, the mean serum total and unbound E2 concentrations were significantly higher in patients with cirrhosis than in normal men. The most consistent abnormality and the one uniformly present was a supranormal E2 to testosterone ratio, as calculated from serum concentration of total or unbound steroids. These findings suggest that changes in the relative balance between circulating estrogen and androgen may play some part in the pathogenesis of gynecomastia in hepatic cirrhosis. The mean serum luteinizing hormone concentration was elevated in patients with cirrhosis, whereas that of follicle-stimulating hormone did not differ from normal.