A seroprevalence survey of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV), was conducted using serum samples obtained from 5813 health care workers (HCWs) in five public hospitals in the Latium region of Italy, during the 1985 vaccination campaign against HBV. The seroprevalences of HBV, HCV and HIV were 23.3% [95% confidence interval (CI) = 22.3-24.4%], 2% (95% CI = 1.6-2.4%) and 0.07% (95% CI = 0.001-0.13%), respectively. In a logistic regression model, sex, increasing age, all job categories vs. physicians, dental treatment in the previous six months, and needlestick injury during the previous year were significantly associated with HBV. Conversely, no occupational and community risk factors, but only history of blood transfusion were significantly associated with HCV. Nevertheless, the documented risk of HCV as well as of HIV transmission through percutaneous and mucocutaneous exposure to blood and body fluids should lead to continued efforts to minimize risks of infection by enhancing the compliance of HCWs with vaccination against HBV and adherence to infection control measures, and by introducing safer devices and techniques.