More than most diseases, acquired immune deficiency syndrome (AIDS) appears to elicit highly negative, fearful, and prejudicial attitudes. In the study reported here, medical students read one of four patient vignettes. The vignettes were identical in content except that the patient was identified as having either AIDS or leukemia as either homosexual or heterosexual. The students then completed a set of objective measures that assessed their attitudes toward the patient portrayed in the vignette. Multivariate and univariate analyses of variance of their responses revealed that the students held negative and prejudiced attitudes toward both the AIDS and homosexual patients. This finding suggests that medical educators should recognize that many students have stigmatizing, negative attitudes toward homosexuals and patients with AIDS. These educators should promote greater sensitivity, knowledge, and understanding among medical students of those at risk for AIDS and AIDS patients.