This study examines women's vulnerability to sexually transmitted diseases (STDs) in Sringeri Taluk, a rural sub-district of Karnataka in South India. It consisted of a first phase of ethnographic research that examined how socio-political, economic and cultural factors and processes may increase women's vulnerability to STDs; and a second phase of epidemiological research that investigated specific questions arising from the first phase. Ethnographic research, conducted between July 1997 and September 1999, revealed three main sources of women's vulnerability to STDs: (1) the experience and embodiment of economic and socio-political disadvantage—based on caste, class and gender—through limitations on opportunity and choice, trafficking and prostitution, and violence against women within the home and without; (2) the State through the promotion of alcohol sales and the failure to prevent trafficking in women and prostitution; and (3) the health care system through which socio-political and economic inequalities are reinforced. A cross-sectional survey was conducted between April and July 1999. The study population, selected through a stratified, multistage cluster sampling procedure, consisted of 410 currently married women between the ages of 15 and 50 years and 303 men (including 249 spouses of interviewed women) between the ages of 15 and 60 years residing in villages within a 30 km radius of Sringeri town. The overall prevalence of bacterial STDs was low (2%) in contrast to the prevalence (10%) of markers of HBV infection (past and current). Approximately a third of women reported having experienced marital violence. In multivariate analyses, reports of violence were significantly associated with household-level (caste and class) and intra-household (women's economic autonomy and husband's alcohol consumption) factors. Lastly, the results highlighted the need for STD prevention education efforts to pay attention to the language that is used to convey ideas regarding risk and vulnerability and the need for condom promotion efforts to take into account issues of sexual pleasure and intimacy and to address repercussions that women may face as a result of suggesting condom use to their husband, particularly violence. Reducing women's vulnerability to STDs hinges on addressing inequalities experienced by women—as individuals and as members of households.