The principles of evolution are finding new applications in medicine, but little is known about the role of evolutionary biology in medical curricula. To determine which aspects of evolutionary biology are included in medical curricula and the factors that influence this, a questionnaire was sent to all deans at North American medical schools who are responsible for curricula. The questionnaire asked about content areas in the curriculum, their perceived importance, and the factors that influence the amount of coverage given to those areas. Forty-eight percent of the deans who responded considered evolutionary biology important knowledge for physicians. Only 32 percent of the respondents reported that their schools covered at least 8 of 16 core topics in evolutionary biology, and only 16 percent of the schools reported having any faculty with a PhD in evolutionary biology. Lack of time in the curriculum and lack of faculty expertise are the main perceived impediments to increased teaching of evolution. We conclude that the role of evolutionary biology as a basic medical science should be carefully considered by a distinguished group of biologists and medical educators. In the meanwhile, undergraduate educators need to recognize that, for now at least, most future physicians must learn evolutionary biology as undergraduates if they are to learn it at all.