Background: The appropriate use of antiretroviral medications to protect against infection with human immunodeficiency virus (HIV) is unclear in cases of sexual assault of children, for whom the perpetrator's risk of HIV is often unknown, and physical proof of sexual contact is usually absent. Objective: In an effort to clarify prescribing practices for HIV post-exposure prophylaxis (PEP) at our institution, we examined records of all children tested for HIV for prevalence of infection, our experience with prescribing PEP, and follow-up rates. Design/methods: Medical records at a sexual abuse clinic of all children tested for HIV during a 38-month period were reviewed for information concerning risk factors for HIV acquisition, STI test results, and PEP experience. Children were defined as PEP-eligible if they were within 96 hours of assault, and there was a report of sexual contact with the potential to transmit HIV. Results: One thousand seven hundred and fifty children were tested for HIV during the study period. Five children had a positive HIV ELISA, but only one child was confirmed HIV-positive. Three hundred and three children were eligible to receive HIV-PEP, but it was only offered to 16 (5.3%), of whom 15 accepted the medications. None of the children prescribed PEP completed follow-up, but 11 children had limited follow-up. Conclusions: Our results indicate that the prevalence of HIV infection among sexually abused children in our population is low, and follow-up rates are poor. Intensive efforts to try to ensure follow-up are warranted whenever PEP is prescribed. Further research may help better define the efficacy of PEP in sexually abused children and adolescents. (Contains 1 figure and 3 tables.)