In 17 out of 176 cases of early syphilis (seropositive syphillis I; syphilis II) liver function tests yielded a positive result. In these patients a significant increase in the serum IgG, IgM and coeruloplasmin levels and a decrease in t4e transferrin level was found. The concentrations of alpha-2-macroglobulin and of beta-1-C-globulin were practically uneffected. Liver biopsy revealed hepatitis of variable severity in 13 patients with focal necroses or a proliferative process effecting the walls of the central veins, the arterioles and the branches of the portal vein. In 7 cases the presence of Treponema in the liver was demonstrated.