Since the beginning of the epidemic sex workers have experienced a heightened burden of HIV across settings, despite their higher levels of HIV protective behaviors (UNAIDS, 2009). By gaining a deeper understanding of the epidemiologic and broader policy and social context within which sex work is set one begins to quickly gain a sense of the complex backdrop for increased risk to HIV among sex workers. This backdrop includes the critical role of stigma, discrimination and violence faced by sex workers, as well as, the importance of community empowerment and mobilization among sex workers to address these regressive forces. The eight country case studies work to highlight the experiences of diverse populations of and contexts for sex work across settings.