Screening of 701 prostitutes in Delhi for HIV antibodies by a competitive ELISA test and supplementary Western blot test showed that only one of them was infected. Of the 4,572 samples from the patients attending a sexually transmitted disease clinic in Delhi, none showed evidence of HIV infection. In contrast to this low frequency of HIV infection in Delhi, a much higher frequency has been reported to the Indian Council of Medical Research from major metropolitan centers on the coast of India, namely, Bombay and Madras and their surrounding areas. It is possible that the infection is making inroads from these coastal areas to the interior of the country.