The increasing number of mothers of young children in the work force and the resultant escalated use of child-care facilities has had a marked effect on the epidemiology of infectious diseases in young children. Children attending child care are at high risk for respiratory and gastrointestinal tract illnesses. The high prevalence of infectious diseases in the child-care setting is accompanied by high usage of antibiotics, which in turn has resulted in spread of antibiotic-resistant organisms. The infectious disease standards of the American Public Health Association/American Academy of Pediatrics guidelines were developed to prevent and limit transmission of infectious diseases in the child-care setting. Adherence to these standards is essential but will not completely eliminate the increased risk of infectious diseases in child-care settings. New challenges need to be addressed to assure that optimal health promotion and disease prevention is practiced in child-care settings. We approach the 21st century with a vast amount of medical knowledge, molecular technology, highly effective vaccines, and powerful antimicrobial agents. However, at the same time we face many unsolved serious problems, such as preventing or controlling the emergence and spread of antibiotic-resistant organisms that adversely affect our ability to treat infectious diseases. Further research is needed concerning the relations between child care, the use of antibiotics, and transmission of antibiotic-resistant organisms in order to design and implement the most effective strategies for preventing or controlling antibiotic resistance. The potential risk for transmission of HIV in the child-care setting also needs to be recognized, and procedures to prevent transmission of blood-borne pathogens need to be followed. Monitoring compliance with national standards for child-care facilities, dissemination of information concerning infectious diseases and use of antibiotics, and development and use of new vaccines are strategies which should be used to help protect the health of children in child-care environments.