PIP: Blood samples were obtained from six HIV-infected IV drug users attending the Indian Council for Medical Research Clinic at Imphal, the capital of Manipur state, as part of a study to analyze the sequences of the third variable region (V3) of the HIV envelope in that population. 18 sequences were obtained from the study participants, men aged 24-29 years. A fragment of the envelope gene encompassing the entire V3 loop and partial sequences from the third conserved region was sequenced, while amplifications were performed on DNA extracted directly from patient peripheral blood mononuclear cells to avoid the introduction of artifacts during cell culture. One set of viruses seems to be most closely related to a prototypical virus recovered from IV drug users in Thailand (Thai B), while the other sequences clustered more closely with a North American clade B virus (HXB). Sequences recovered from one person are rather diverse.