Human T cell leukemia virus type II (HTLV‐II) is endemic in a number of native American populations and high rates of infection have also been demonstrated in intravenous drug abusers (IVDAs). Studies of virus isolates in the latter population have shown the existence of two closely related subtypes of the virus, HTLV‐IIa and HTLV‐IIb. To characterize the viruses present in native Americans, we analyzed by nucleotide sequence analysis the proviruses from the Wayu, an aboriginal population residing in Colombia, South America. The results showed HTLV‐IIb infection in this population, and also demonstrated remarkable conservation of sequence when compared to the proviruses in IVDAs.