The number of persons in the United States potentially in contact with rabid humans has increased in recent years because of labor-intensive medical care, longer survival times, and care in two or more hospitals. Many of these persons request rabies prophylaxis, and their physicians prescribe it because of their insecurity, a situation that is expensive and often unnecessary. Records of the Centers for Disease Control and the literature were reviewed to examine the current practice of prophylaxis of contacts and the actual need for it. Rabies virus is present in a variety of human fluids and tissues during the first five weeks of illness, but there are only four well-documented reports of human-to-human transmission--all in corneal transplant recipients. Prophylaxis of contacts of 14 rabid patients was predominantly for saliva exposure to open wounds or mucous membranes and was given most often to medical personnel having the greatest contact with the patient. Although it has never been documented, human-to-human transmission of rabies following saliva exposure remains a theoretical possibility. Virus shedding by rabid patients should be studied thoroughly in the future. Recommendations for managing contacts of rabid patients are presented.