This report presents the findings from a study investigating homosexually active men’s awareness and access to post-exposure prophylaxis (PEP) following potential sexual exposure to HIV. The study consisted of two arms. In the first, identical questions on PEP were asked in the Gay Men’s Sex Survey in 2003 and 2005 to examine population level and sub-group changes in awareness over a period where the public profile of PEP was increased. In the second part, men who had at least one experience of attempting to access PEP took part in detailed one-to-one interviews. This qualitative data offers a detailed insight into men’s awareness of the treatment, what prompted them to seek help, their satisfaction with the clinical experience and follow-up, and their subsequent behavioural intentions and practices in relation to HIV risk. The remainder of this chapter offers a brief introduction to PEP and its use, by reviewing existing academic research and commentary on PEP (mainly focussing on its use outside of the occupational setting). It also provides background information on developments relating to PEP following sexual exposure in the UK context. Chapter 2 presents the quantitative data, and Chapter 3 presents a thematic analysis of the information gained from the one-to-one interviews. In the final chapter, we present conclusions drawn from the findings of both arms of this investigation, as well as practical recommendations regarding meeting the PEP-related needs of individual men at risk of HIV exposure, and the needs of professionals working towards full implementation of the UK guidelines on PEP following sexual exposure to HIV.