Children can acquire infection with the human immunodeficiency virus in four ways: (1) vertical transmission from the mother, through infection carried by blood, (2) blood products or transplanted organs, (3) child abuse, and (4) for adolescents, through sexual intercourse. Three-quarters of the reported cases have resulted from perinatal transmission. Most of these children appeared normal at birth. Infected infants become symptomatic somewhere between 8 and 15 months of age. Initial signs are failure to thrive, chronic diarrhea, and developmental delays. Enlarged lymph nodes, liver, and spleen also develop. Unlike adult patients, these children are peculiarly susceptible to common bacterial infections like middle ear infection and pneumonia. The majority live less than 3 years and die with opportunistic infections. Management of perinatal AIDS infections has to begin with the education of women in the high risk group. The pediatrician should also be informed if the mother is antibody-positive. Shelter or foster care needs raise difficult issues. Infected children should probably not attend day care until age 3. Prevention of pediatric AIDS means the prevention of infection of women of childbearing age, the prevention of pregnancy in women known to be infected, and consideration of pregnancy termination in infected individuals. 17 references.