An HTLV-II was isolated from a Ghanaian female patient with ARC and anti-HTLV-II antibody by cocultivation of PBMC with Molt-4 cells. A part of the 5' LTR of this virus was sequenced. Sequence homology between this virus and the corresponding sequence of Mo, the prototype of HTLV-II, is 97.4%. Furthermore, this virus is a member of the HTLV-IIa group, which was proposed by Hall et al. This is the first report of an HTLV-II sequence from Africa confirmed not only by serological evidence, but also by genomic analysis. This finding will provide useful information for considering the spread of HTLV-II in the world and the evolution of the HTLV group.