Among 130 male patients admitted during a 30-month period with acute hepatitis in the Copenhagen Clinic for Infectious Diseases, 31 were homosexuals. Hepatitis B virus occurred in an endemic fashion in the homosexual subpopulation while hepatitis A infection caused a small epidemic among homosexuals during the winter 1977-78. The course of these infections showed no serological or clinical differences from the findings in 38 heterosexual male patients seen during the same period.