Concern regarding an occupational risk of acquiring human immunodeficiency virus (HIV) infection may influence surgeons' willingness to operate. A questionnaire survey of all orthopedists in the five cities with the most cases of acquired immunodeficiency syndrome (AIDS) was conducted to assess attitudes and practices. Questionnaires were completed anonymously by 325 of 510 orthopedists. In the previous year, 43 percent had examined or operated on an HIV-infected patient, and at least 90 percent who had had an opportunity to operate on an HIV-infected patient had chosen to do so. Decisions to operate did not appear to be based on hospital requirements, perceived ethical obligations, or knowledge of HIV transmissibility. Most orthopedists (85 percent) claimed the right to order preoperative HIV testing of high-risk patients, but such testing was ordered infrequently. Although most orthopedists believed they could not be compelled to operate and that ethically they could refuse when their health was threatened, they almost always were willing to treat HIV-infected patients.