Acute viral hepatitis B is considered to be an occupational risk to health-care workers worldwide. At the 1977 annual meeting of the Danish Society of Surgeons, 224 participants were examined for the presence of hepatitis B surface antigen (HGsAg) and antibody to HBsAg (anti-HBs) with use of a radioimmunoassay. None of the surgeons was HBsAg-positive, but 23% had anti-HBs. The prevalence of anti-HBs was five times higher among these surgeons than that in an age-matched control population. Hepatitis acquired during occupation as a surgeon was predominantly of type B, in contrast to hepatitis acquired before entering the surgical profession. Danish surgeons must be regarded as a group at high risk of hepatitis B infection.