We screened 351 employees of a county hospital for the presence of antibodies against hepatitis A virus (anti-HAV). Hospital staff tested was from the department of paediatrics, infectious diseases unit, institute of microbiology, hospital kitchen, and the day-care centre. 292 donors from the hospital blood bank served as a control group. The prevalence of anti-HAV in indigenous hospital staff less than 30 years of age was extremely low, but showed an age-dependent increase to 69 per cent in personnel more than 50 years of age. The anti-HAV prevalence rate of indigenous health-care workers did not show significant differences from that of volunteer blood donors. The high prevalence of anti-HAV in non-indigenous employees with almost total exposure in persons more than 40 years of age most probably reflects the high risk of childhood infection in endemic regions. We conclude that the risk of occupational exposure to HAV in the hospital setting appears to be small. Active immune prophylaxis with hepatitis A vaccine should be restricted to employees with frequent contact with HAV-contaminated faeces. Pre-vaccination screening for anti-HAV is cost effective in indigenous hospital staff more than 30 years of age and in all non-indigenous employees.