In this article I consider the field of HIV treatment and prevention in light of poststructural feminist critiques of the self-evidence of matter. Both HIV and poststructural feminist theory are viewed in relation to the current state of HIV scientific research of which it has been said: ‘much remains left to the imagination’ (McCune, 2001, emphasis added). Importantly, it is in the absence of ‘real’ knowledge of bodily matter and virus, that imagination is presumed by science as a fall back. (...) Paradoxically, recent debate within feminist theory provides an almost perverse counter to this way of characterizing the struggle against HIV. Rather than considering imagination as something outside or external to the ‘real’, there is now substantial argument suggesting that imagination is always already present and inherent to the ‘real’. In the course of this paper, these differing positions of science and feminist theory are used to challenge and extend each other. The empirical matter of HIV medical science is shown as evidence of matter beyond the normative insistence of (human) language. On this basis, a theory of performativity - devised by Judith Butler and extended by Karen Barad - is argued as grounds for a methodologically expanded science. (shrink)