A randomly selected sample of physicians in three large cities was asked to read one of four vignettes describing a patient. They then completed a set of objective attitude measures eliciting their reactions to the patient described in the vignette. The vignettes were identical except that the patient's illness was identified as either acquired immunodeficiency syndrome (AIDS) or leukemia and the patient's sexual preference as either heterosexual or homosexual. Harsh attitude judgements were associated with the AIDS portrayals, as well as much less willingness to interact even in routine conversation when the patient's illness was identified as AIDS. Increasing numbers of AIDS patients will be seeking medical attention from physicians in all areas of the country and it will be important for health care professions to develop programs which counter unreasonable stigma and prejudicial attitudes that may be associated with this illness.