The HIV/AIDS epidemic has completed its second decade in Latin America and the Caribbean, the latter being the second most heavily affected region in the world. In UNGASS (2001), governments renewed their commitment to confront the epidemic with adequate prevention and care. This review begins by characterizing the regional epidemic as concentrated on vulnerable groups (except for certain areas of generalization). Subsequently, we summarize the prevention work with each target group and contrast it with the epidemiological profile, concluding that the epidemic was not addressed in either timely or sufficient fashion in vulnerable groups, all of which are linked to other population groups. We also point out conditions that could foster greater impact by prevention strategies and analyze ways by which prevention activities could be better integrated with impact/reduction measures. Finally, we analyze the available information on expenditures in prevention.