AIDS, Drugs and Prevention brings together a range of international contributions on the research, theory and practice of developing community-based HIV prevention. It aims to understand how individual actions to prevent HIV transmission are constrained and encouraged by situational and social context. Drawing on ethnographic and epidemiological research among populations of drug users, sex workers and gay men, it explores how future HIV prevention interventions can target changes at the level of the individual as well as at the level of the community and wider social environment.