Phenotypic change and broader coreceptor usage by HIV-1 have been associated with disease progression. HIV-1 coreceptor usage by primary isolates obtained from HIV-1-infected and HIV-1/HTLV-II-coinfected individuals was determined. HIV-1 was isolated from 15 of 20 HIV-1-infected and 17 of 24 HIV-1/HTLV-II-coinfected individuals. None of the isolates from either the HIV-1-infected or the coinfected group infected CCR5delta32 PBMCs, suggesting that they all were R5-tropic. Further, both spontaneous and PHA-stimulated production of MIP-1beta and RANTES were similar in HIV-1-infected and coinfected individuals. These data indicate that coinfection with HTLV-II has no effect on HIV-1 coreceptor usage or ex vivo beta-chemokine production.