This study aimed to identify socio-cultural and reproductive health correlates of knowledge about AIDS among rural women using multivariate analysis of 1998–1999 National Family Health Survey (NFHS) data from two Indian states, Maharashtra and Tamil Nadu, where the urban HIV prevalence is relatively high. Analysis using multiple logistic regression was undertaken, modelling women's knowledge of AIDS, of whether the disease can be avoided, and of effective means of protection. Although 47% of all rural women in Maharashtra were aware of AIDS only about 28% knew that one can avoid it, and only about 16% possessed correct knowledge about its transmission. In Tamil Nadu, where overall 82% of rural women had awareness of AIDS, about 71% knew that one can avoid the disease but only about 31% possessed correct knowledge about its transmission. In both states, women from socially and economically backward groups had lower odds both of having awareness of AIDS and knowledge of ways to avoid getting the disease. Associations with socio-cultural and reproductive variables and the impact of contact with family planning services differed in the two states. The spread of the epidemic to rural areas presents a need actively to disseminate AIDS related knowledge for health protection rather than waiting for knowledge to follow the appearance of the disease in communities. Approaches to health promotion that do not consider differing contextual factors are unlikely to succeed. In particular, innovative strategies to disseminate knowledge among disadvantaged population groups are needed