We have previously demonstrated that intracellular expression of an RNA aptamer termed RRE40, which was selected in vitro to bind HIV Rev 10-fold much tighter than wild-type RRE, efficiently protected human CD4+ T cell line, CEM, from HIV-1. In this study, to evaluate the efficacy of the RRE40 RNA in clinical settings, polyclonal CD4+ peripheral blood lymphocytes (PBLs) were transduced with retroviral vectors expressing RRE40 decoy RNA and then challenged with clinical isolates of HIV-1. In contrast to the control cells transduced with vectors expressing control tRNA, intracellular expression of RRE40 RNA more effectively inhibited HIV-1 replication in CD4+ PBLs. However, transient and diminished inhibition, rather than complete inhibition, of HIV-1 replication in PBLs expressing RRE40 decoys have been observed. These results suggest that RRE40 decoy RNA would be useful to inhibit HIV-1 replication in cells. However, development of more efficient gene transfer protocols and/or more effective decoy RNAs would be needed to apply RNA decoy to modulate HIV-1 patient.