Human immunodeficiency virus (HIV) type 1 disrupts the T cell receptor (TCR) variable region (V) beta repertoire in CD8 T cells by impairing thymic capacity and skewing postthymic cellular maturation. The TCR repertoire was examined using spectratyping of CDR3 length diversity within CD45RA and CD45RO CD8 T cells in HIV-infected and healthy children. In healthy children, CDR3 lengths displayed Gaussian distribution in both CD45RA and CD45RO subsets. Vbeta families in HIV-infected children displayed a large proportion of perturbations in both subsets. High virus load and advanced immunosuppression correlated with increased perturbations within CD45RA but not CD45RO CD8 T cells. After therapy and virus suppression, there was rapid reestablishment of Gaussian distributions in CD45RA cells. HIV-1-induced disruption of TCR diversity within CD45RA CD8 T cells correlates with disease progression. Suppression of viral replication by treatment results in the rapid correction of TCR diversity in this CD8 subset because of emergence of new T cells from the thymus.