The criminalisation of HIV transmission and exposure has attracted a good deal of attention from academic commentators. While some of this commentary has accepted that criminal law has a place as a response to disease and infection in some limited circumstances (Grant 2008), others reject it outright (Houlihan 2011). In this chapter, I signal my own agreement with some of the key arguments against criminalisation, and develop these in a rather different direction. Whether by accident or design, the criminalisation of HIV tends to foster and encourage three common misperceptions. The first of these is the perception of HIV that it is highly transmissible, such that any single instance of unprotected sex with an infected person is highly likely to lead to infection. Where an HIV positive person is undergoing anti-retroviral therapy, they are much less infective than commonly imagined. The second is that HIV is likely finally to be fatal, with a high likelihood of death from an AIDS-related illness. Without wishing to diminish or trivialise the experience of being HIV positive, it is the case that anti-retroviral therapy means that in the last decade transmission is much less likely to lead to an early death than is commonly believed, or than was the case in the 1980s and early 1990s (Gable et al 2009: 260). The third misconception is that like rape or violent assault, HIV transmission is necessarily a matter of a harm inflicted upon a victim by an HIV positive individual concealing his infection, when we might alternatively regard it as the consequence of mutual risk-taking or of contexts that might make disclosure difficult (Weait 2001).