SummaryIn this study, we asked whether there is a difference in the number of CD4+and CD4−peripheral blood monocytes as CD4+T cells decrease during HIV-mediated immunodeficiency. Monocytes and T cells from 90 HIV-positive and 43 HIV-negative persons were analyzed by flow cytometry. The 90 HIV-positive patients represented the entire spectrum of CD4+T-cell counts. We report that as CD4+T cells decrease, the number of CD4+monocytes decrease in parallel. Moreover, significantly higher CD4+monocyte counts were observed in persons with early stage HIV disease, i.e., >800 CD4+T cells/mm3, than in HIV-negative persons with >800 CD4+T cells/mm3. Potential implications of these findings are discussed.