Specialists in adolescent medicine must work with educators to ensure that the widest possible adolescent population receives information on the nature of AIDS, how it is transmitted, and how it can be prevented. Calls for the HIV testing of adolescents must be carefully assessed. The purposes proposed for such testing are to determine the prevalence of AIDS in this population, to protect public health, and to benefit the adolescent. Opponents of testing argue that there is no treatment available upon diagnosis, test results are difficult to interpret, a positive result could provoke severe mental problems for the adolescent, and disclosure of results could lead to severe stigma and discrimination against the subject. Overall, the likelihood of harm outweighs the possible advantages of testing. Where testing is sought by an adolescent or recommended by a physician or other professional, extensive counseling should be available, and confidentiality should be ensured. When AIDS researchers target high-risk adolescent groups for study (homeless or street youth, homosexual youth, intravenous drug users, and sexually active adolescents with high rates of sexually transmitted disease), they should make every effort to ensure that research results are not used to discriminate against such adolescents and advocate appropriate services. Other issues that must be addressed are informed consent for testing, notification of test results, contact tracing and the duty to warn, and incarcerated youth.