This chapter asks why should we be concerned with “biotheory”? Is not biopolitics itself always already theoretical? The term biotheory is demonstrated not just to flag the centrality of bios (life, ways of life, living), but also to underline the continuing importance of critical theory to this area of study. To be sure, a split between the philosophical/theoretical concerns of biopolitics and specific interdisciplinary case studies has long been acknowledged, but, on the whole, this is generative when a level of abstraction must meet new determinants. This is particularly true of a body of theory broadly viewed as materialist (historical, Marxist and post-Marxist, cultural and “new”), especially after the collapse of actually existing socialism in the late eighties and early nineties and the rationalization of neoliberal globalization ever since.