India has a large population of HIV-infected individuals, but the amount of information available about this population is small and not commensurate with the population's size. Here, we report the age and sex for 11,925 individuals tested for HIV infection in a nongovernmental setting over a 36-month period. The samples were derived from 161 sites located in different parts of the country and the odds of HIV infection among males was 2.27 times that for females. Of the samples from males and females tested, 50 and 65%, respectively, were in the 16-35 year age group. Of the seropositive samples excluding less than 1 year of age, 92% were in the 16-50 year age group. Analysis of this testing data provides limited but valuable information on the HIV epidemic in India.