Disclosure of the diagnosis of human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) to a child is a controversial and emotionally laden issue. To understand the factors that affect the process of disclosure and its consequences, we studied 99 parent-child dyads recruited from patients being treated at the National Cancer Institute (NCI). Parents and HIV-infected children were interviewed and administered several standardized measures. Parental depression, family environment, social support satisfaction, socioeconomic status, child and parent gender, child's age, parental HIV serostatus, and disease severity were used to predict disclosure status. Results indicate that the majority of caregivers do disclose the diagnosis to the child, usually with no ill effects, and that age is the most significant predictor of whether or not a child has been told. The Centers for Disease Control and Prevention currently estimate that there are over 6611 children with AIDS (under age 13), and 2184 adolescents with AIDS (ages 13-19) in America. As an increasing number of children who are born infected with HIV live to older ages, the question of when and how to talk with them about their illness becomes more crucial. In addition to the growing number of children infected with HIV, there are many thousands of children profoundly affected by the impact of this disease on a close family member--a mother, father, sibling, or other relative in the kinship network. Yet, the initial reaction most adults have upon learning of their own, or of a family member's, HIV diagnosis is that the diagnosis must be kept a closely guarded secret. One reason frequently cited by parents and family members is their fear that the stigma of AIDS will have a negative impact on their children and their families. Disclosure of an HIV diagnosis to a child is a controversial and emotionally laden issue in the pediatric health-care community as well. However, no systematic research has studied the issues that surround disclosure of an HIV diagnosis to the patient and the factors that predict disclosure.