Cellular senescence is activated by numerous cellular insults, in particular those driving cancer formation, resulting in stable proliferation arrest and acquisition of specific features. By self-opposing to oncogenic stimulation, senescence is considered as a failsafe program, allowing, when functional, to inhibit cancers occurrence. Compelling evidences suggest a tumor suppressive activity of caspase-2, eventually independently of its effect on cell death. The original results described here demonstrate that this tumor suppressive activity of caspase-2 is mediated, at least in part, by its pro-senescing activity. Indeed, we have demonstrated in vitro and in vivo that loss of function of caspase-2 allows to escape oncogenic stress induced senescence. These results are discussed in the context of known tumor suppressive activity of caspase-2.