PURPOSE: To estimate the risk for acquiring an infectious disease during cardiopulmonary resuscitation (CPR) or CPR training and to identify strategies to minimize that risk. DATA SOURCES: English-language articles published since 1965 were identified through a search of the MEDLINE database and selected bibliographies. STUDY SELECTION: Studies that contained information about transmission of infectious organisms, particularly HIV and other bloodborne viruses that might be transmitted through mouth-to-mouth ventilation, contact exposures, and needlesticks during CPR. DATA EXTRACTION: Descriptive and analytic data from each study. DATA SYNTHESIS: Fear of acquiring infection, especially HIV infection, can delay prompt initiation of mouth-to-mouth ventilation. Although pathogens can be isolated from the saliva of infected persons, salivary transmission of bloodborne viruses is unusual and transmission of infection has been rare: Only 15 documented cases have been reported. Most of these cases involved a bacterial pathogen, such as Neisseria meningitidis. Transmission of hepatitis B virus, hepatitis C virus, or cytomegalovirus during CPR has not been reported; all three reported cases of HIV infection acquired during resuscitation of an infected patient resulted from high-risk cutaneous exposures. There have been no reports of infection acquired during CPR training. Simple infection-control measures, including use of barrier devices, can reduce the risk for acquisition of an infectious disease during CPR and CPR training. Postexposure protocols can further protect potential rescuers and trainees. CONCLUSIONS: The benefit of initiating lifesaving resuscitation in a patient in cardiopulmonary arrest greatly outweighs the risk for secondary infection in the rescuer or the patient. Nevertheless, use of simple infection-control measures during CPR and CPR training can reduce a very low level of risk even further.