The kinetics of peptide presentation by major histocompatibility complex class I (MHC-I) molecules may contribute to the efficacy of CD8⁺ T cells. Whether all CD8⁺ T-cell epitopes from a protein are presented by the same MHC-I molecule with similar kinetics is unknown. Here we show that CD8⁺ T-cell epitopes derived from SIVmac239 Gag are presented with markedly different kinetics. We demonstrate that this discrepancy in presentation is not related to immunodominance but instead is due to differential requirements for epitope generation. These results illustrate that significant differences in presentation kinetics can exist among CD8⁺ T-cell epitopes derived from the same viral protein.