Influenced by both 19^th-century literature and popular representations of science, the figure of the medical doctor in steampunk fiction is marked by ambiguity. At the same time a scientist, a wizard and a mechanic, the steampunk doctor exists halfway between respectability and illegitimacy, a manipulator of bodies, a wielder of mysterious powers, a respectable and ominous character at the same time. Their role includes but is not limited to healing bodies. Indeed, steampunk examines the consequences extraordinary medical discoveries can have on both individuals and societies. It questions the meaning of “improvement” in the context of medicine, and whether it is ethical for medical practitioners to bring human bodies beyond their normal state, to the point that normality itself has to be re-defined. This paper describes the figure of the steampunk doctor and details the place and power of medicine in steampunk worlds. On the one hand, the steampunk doctor can modify bodies at will, bringing bio-engineering on a par with regular engineering, and leading to questions about the boundaries (ontological and ethical) between humans and objects, living and inanimate matter. On the other hand, their work on individual bodies can lead to transformations of their society as a whole, by modifying entire groups to suit social or political agendas, or in a quest for personal power. In the end, the figure of the steampunk doctor brings to the forefront some ethical questionings about medicine, healing, bio-engineering and human enhancement that are very relevant to the present times, in spite of the deceptively retrospective aesthetics.