Implementation of a hospital policy for health care workers exposed to the human immunodeficiency virus (HIV) or hepatitis is discussed, using a model program established by San Francisco General Hospital (SFGH). Occupational Safety and Health Administration (OSHA) guidelines on blood-borne pathogens require a comprehensive program for management of occupationally exposed workers at all health care institutions. To meet the need of immediate assessment, SFGH has established a 24-hour hotline staffed by several clinicians. These clinicians provide risk assessment at the time of the call, and the 24-hour pharmacy service, using an anonymous system to protect the worker, can have zidovudine prophylaxis available within five minutes for workers potentially exposed to HIV. Hepatitis prophylaxis focuses on hepatitis B immunization and administration of hepatitis B immune globulin to workers who have been exposed. Ongoing medical management involves monitoring the adverse effects of zidovudine, ensuring that workers receive any workers' compensation benefits to which they are entitled, providing pretest and posttest counseling for exposed workers and their significant others and families, and supplying appropriate documentation. Confidentiality is essential for worker participation in the program. The costs of such a program are not insignificant but must be borne by the institution if it is to take care of its health care workers. Institutional policies and procedures must address all the components of postexposure management, as well as the issues related to HIV- and hepatitis B-infected health care workers. Sufficient staffing and funding, confidentiality, and prevention are the keys to a successful program.