Steroid hormone treatment of patients with infectious hepatitis results in a rapid decrease of serum glutamic pyruvic transaminase and serum glutamic oxalacetic transaminase levels. After completion of hormonotherapy another short-term increase of the two hormone levels is possible. Under the effect of steroid hormones the cerulo-plasmin level returns to the normal, but after hormonotherapy has been discontinued the level of this hormone increases again, especially so when infectious hepatitis is not readily amenable. There was no increase of the ceruloplasmin level when hyperbilirubinemia was persistent in reconvalescence. The serum cholinesterase level returned to the normal more rapidly when hormonotherapy was instituted (as compared to the cases when no hormones were applied). In patients with persistent hyperbilirubinemia, and especially in those with exacerbated hepatitis the serum cholinesterase level decreased again after hormonotherapy had been discontinued. The above-mentioned disorders in the activity of serum cholinesterase and ceruloplasmin during the period following completion of hormonotherapy reflect either exacerbation of hepatitis or persistence of hyperbilirubinemia.