Adeno-associated virus has been developed for use as a gene transfer vector. To understand the impact of AAV capsid-specific CD8⁺ T cells on AAV-mediated gene transfer, we identified CD8⁺ T cell epitopes for AAV-2 and AAV-8 capsid in C57BL/6 (H-2^b MHC haplotype) and BALB/c (H-2^d MHC haplotype) mice. Mice of both the H-2^b and the H-2^d haplotypes recognized epitopes on AAV-2 and AAV-8 capsid. T cells from H-2^b mice recognized an epitope that was conserved between AAV-2 and AAV-8 capsid. Cross-reactivity of AAV-specific CD8⁺ T cells induced by different AAV serotypes may have important implications for gene transfer. Identification of these epitopes will facilitate studies of immune response to AAV capsid in mouse models.