Monographs commemorating the work of Charles Darwin (1809–1882) typically cover a wide range of topics on which the theory of evolution has thrown some light. The influence of evolutionary thought on medicine was, until recently, often left in the dark, however. Yet evolutionary biology has crossed path with medicine more than once during the last 150 years, and the changing nature of these interactions has only begun to be examined historically and philosophically. Since more than 20 years, researchers are increasingly addressing the nature and causes of health and disease from an evolutionary standpoint. In this chapter after surveying the reception of Darwin’s work by medical doctors and the relation between evolutionary thinking and eugenics, I argue that distinguishing ‘evolutionary’ from ‘Darwinian’ medicine will help us assess the variety of roles that evolutionary explanations can play in a number of medical contexts. Because the boundaries of ‘evolutionary’ and ‘Darwinian’ medicine overlap to some extent, they are best described as distinct ‘research traditions’ rather than as competing paradigms. But while evolutionary medicine does not stand out as a new scientific field of its own, Darwinian medicine is united by a number of distinctive theoretical and methodological claims. For example, evolutionary medicine and Darwinian medicine can be distinguished with respect to the styles of evolutionary explanations they employ. While the former primarily involves ‘forward looking’ explanations, the latter depends mostly on ‘backward looking’ explanations. A forward looking explanation tries to predict the effects of ongoing evolutionary processes on human health and disease in contemporary environments (e.g., hospitals). In contrast, a backward looking explanation typically applies evolutionary principles from the vantage point of humans’ distant biological past (i.e. the Pleistocene) in order to assess present states of health and disease. Both approaches, however, are ultimately concerned with the prevention and control of human diseases. In conclusion, I raise some concerns about the claim that ‘nothing in medicine makes sense except in the light of evolution.