This study assessed the situational and sociodemographic characteristics of children infected with human immunodeficiency virus (HIV) from pediatric sexual abuse. A letter of inquiry was sent to 2147 professionals across health and social service disciplines involved with child abuse assessment, treatment, and prevention. Respondents working in programs where HIV antibody testing of abuse victims occurs and who had identified HIV infection in one or more abused children were sent a survey to assess the demographics of victims, the family/living situation where abuse occurred, alternative risks for HIV infection, bases for diagnosis of sexual abuse and for HIV antibody testing, and profiles of the perpetrator and type of abuse. Of 5622 estimated HIV antibody tests conducted during 113,198 sex abuse assessments, 28 children were infected with HIV and lacked any alternative transmission route to that of sexual abuse. A total of 41 HIV-infected children with a history of sexual abuse were identified. Thirteen cases had alternative risk factors and were excluded from analysis. Sixty-four percent of the 28 victims with sexual abuse as the sole risk factor were female and 71% were African-American. The mean age was 9 years. Coinfection with another sexually transmitted disease (STD) occurred in 9 (33%) cases. Sexual abuse was diagnosed on the basis of a victim disclosure in 21 (75%) cases. The basis for HIV antibody testing was physical findings suggestive of HIV infection in 9 (32%) cases, HIV-seropositive or high-risk perpetrator in 6 (21%) and 2 (7%) cases, respectively, and the presence of another STD in the victim in 4 (14%) cases. Perpetrators were a child's parent in 10 (42%) cases and another relative in 6 (25%) cases.(ABSTRACT TRUNCATED AT 250 WORDS)