Detergent-solubilized murine cytolytic T lymphocytes (CTL) clones were incorporated into Sendai virus-containing synthetic liposomes. When these liposomes were then fused with other CTL clones possessing a different non-cross-reacting specificity, the fusion products were observed to lyse target cells recognized by both parental CTL clones. This method was then used with two H-2-restricted CTL clones of different, non-cross-reacting specificities (anti-H-2b-H-Y or anti-H-2b Moloney leukemia virus). Once again, the fusion products were found to be lytic against both target cells recognized by the parental clones, but in no instance was there any observable lysis of target cells bearing the same nominal antigen in the context of different H-2 molecules. These results provide strong evidence that antigen recognition by H-2-restricted CTL is not mediated by two independent antigen receptors.