This paper describes an Indo-US, research and intervention project for HIV/STI prevention and sexual risk reduction in urban poor communities in Mumbai, India in which formative research established the importance of reduction in alcohol use as one of the central features of the intervention. As a part of formative research, in-depth interviews with married women and men indicated that alcohol had a direct negative effect on marital relationships, violence, household economics and men's involvement in extramarital sex. The project utilized diverse community intervention mechanisms over the course of a three year intervention effort. Comparison of pre-post intervention, cross-sectional samples showed a significant drop in overall use of alcohol in the study communities. Analysis of a longitudinal panel sample identified sub-groups of married men based on their demographic, behavioral and attitudinal characteristics at baseline who stopped drinking during the intervention period. Results also demonstrated that a reduction in men's alcohol use during the intervention period was associated with a reduction in sexual risk behavior and related variables.