Interleukin (IL)‐7 and IL‐15 are cytokines implicated in homeostatic control of the peripheral CD8 T‐cell pool. We compared the effects of IL‐7 and IL‐15 on survival and proliferation of purified human CD8⁺ T‐cell subsets. Low concentrations of either cytokine reduced the spontaneous apoptosis of all subsets, and enhancement of survival corresponded to the extent of Bcl‐2 up‐regulation. Surprisingly, although minimal proliferation of naïve CD8⁺ T cells was observed during the first week of culture with cytokines, a marked expansion of these cells occurred at later time points, particularly in response to IL‐15. This occurred largely without phenotypic change or acquisition of effector function, indicating a dissociation of differentiation from proliferation. Notably, progression of naïve CD8⁺ T cells through several cell divisions resulted in up‐regulation of telomerase and the maintenance of telomere length. These data show that IL‐7 and IL‐15 induce cell proliferation and rescue from apoptosis in a concentration, time and subset‐dependent manner, and have implications for the homeostatic expansion of the naïve CD8⁺ T‐cell pool.