Recent experiences of emerging infections, such as severe acute respiratory syndrome (SARS) and avian influenza (H5N1), have highlighted the risks of serious pulmonary infections from occupational exposures. Occupationally acquired human immunodeficiency virus (HIV) infection could also result in life-threatening, opportunistic lung infections as a result of host immunosuppression. These three occupationally acquired infections are major public health problems that carry with them enormous economic and societal implications. The present review discusses their microbiology, epidemiology and mode of transmission, clinical features, treatment and, more importantly, prevention. Health care workers (HCWs), who are a valuable health care resource especially in the developing nations, are at high risk for acquiring these diseases. Drugs for the treatment of HIV infection are expensive and not widely available in the developing world where they are most needed. As there is no well-recognised effective treatment for SARS and avian influenza, prevention of infection is most important. HCWs should be aware of occupationally acquired infections and know how to protect themselves. Regular training should be provided by all health care institutions on infection control measures and the use of personal protective equipment.