Recommendations were presented for protecting against transmission of human immunodeficiency virus (HIV) in health care settings. There is increasing risk for health care workers to contact blood and body fluids from infected persons. Precautions and recommendations for safety were offered for clinical and laboratory staffs, health care workers and allied professionals, and morticians, along with ways in which transmission can be prevented in the workplace, recommended safety measures for invasive procedures, ways to avoid contamination from tears, and safe ways to provide dialysis treatment for HIV infected patients. Proper ways for cleaning and decontaminating spills of body fluids, laundry methods, and methods for handling contaminated waste products were explained. It was emphasized that all patients must be approached as though they are infected. Persons at risk included professional staff and also those in training. Persons with acquired immune deficiency syndrome (AIDS) employed in health care or clinical laboratory settings numbered 1,875 in July 1987, or 5.8 percent of the 32,395 adults with AIDS. Of health care workers with AIDS at that time, 95 percent showed high risk behavior. There were 33 cases for whom there was no apparent cause. Parenteral exposures during the 10 years prior to AIDS diagnosis were reported in 15 of these cases. Serological testing for HIV infection and management of infected health care workers were discussed.