Medical geography is a small sub-discipline of academic geography. Its presence within histories of geography depends in part upon whether geography is considered as a discipline or whether there is a broader understanding of geographies as forms of practical and popular knowledge. lf we take the second approach, medical geography would seem to be quite important in the development of geographical imaginations. There are connections of cause and responsibility between these popular and academic geographies. Quite often, popular knowledges get treated as precursors of academic disciplines yet the connections are reciprocal and continuing. Medical topics appear in histories of geography under two main guises: as an occasion of environmentalism or as a field of spatial analysis (Mayer 1990). These two form the backbone of this chapter. I begin by indicating some of the ways these two aspects of medical geography have featured in histories of geography. Then, I consider these aspects in the light of three tactics from Foucault's historical writings (see Table 1). I take up the question of the relations between discourses and practices. I look at the processes whereby subjectivities are shaped. Finally, I look at the political issues raised in history writing, illustrating my account with reference to the imaginative geographies '(Said 1978, 55) of AIDS.