The levels of early spliced mRNA and genomic RNA of human immunodeficiency virus (HIV) type 1 in peripheral blood mononuclear cells (PBMC) of 14 patients who were receiving highly active combination antiretroviral therapy for > or =116 weeks were determined. The level of viral genomic RNA was below the level of detection in the plasma of these patients (<50 copies/mL), but cell-associated viral tat, rev, and nef mRNA were detected in 86% (12 of 14) of the patients. Cell-associated viral genomic RNA was detected in 57% (8 of 14) of the patients. Early viral spliced mRNA was detected in the PBMC of all patients who had positive results of testing for HIV-1 genomic RNA, and the level of viral genomic RNA in these patients was 34-2214 copies per 10(6) cells.