Objective: To examine frequency and correlates of physicians' reports of discussions with patients with human immunodeficiency virus (HIV) about complementary and alternative medical (CAM) therapies. Design: Mailed physician survey. Setting: The setting was Eastern Massachusetts. Participants: Participants included 89 physicians caring for patients with HIV. Measurements and Main Results: Physicians were asked how common the use of CAM therapies was among their patients, how useful these therapies were, how often they discussed the use of CAM therapies with new and follow-up patients, and whether they had used a CAM therapy themselves in the last year. We also collected information on physicians' sociodemographic and practice characteristics. Sixty-eight percent (89/130) of physicians responded, and 26% and 5% reported discussing CAM therapies with HIV-infected patients at most new and follow-up visits, respectively. Respondents' attitudes toward the use of CAM therapies were generally positive, and they believed their HIV-infected patients used CAM therapies more than their non- HIV infected patients. The majority (63%) believed that CAM therapies may be helpful for HIV-infected patients. Thirty-six percent (36%) had used a CAM therapy themselves in the last year. In multivariate analyses, only the belief that CAM therapies are helpful was correlated with discussion of CAM therapies (p = 0.006). Respondents' demographic characteristics, training, personal use of CAM therapies, reported visit length, and satisfaction with visit length were not associated with discussion of CAM therapies. Conclusions: Despite awareness that their HIV-infected patients commonly use CAM therapies and positive attitudes towards such therapies, most of these physicians did not routinely discuss CAM therapies with them. Barriers to physician-patient communication about CAM therapies merit further investigation.