In mammals, the term “adult hippocampal neurogenesis” defines the process through which, throughout adulthood, new granular neurons are produced by neural stem cells (NSC) in the subgranular zone (SGZ) in the dentate gyrus (DG) of the hippocampus or, by a population of immature neurons located in the SGZ. Either way, the existence of neurogenic activity in the hippocampus has been correlated with learning, memory formation and behavioral responses to stress, together with the pathophysiology of many brain diseases and mood disorders. Various extracellular and intracellular stimuli have been shown to modulate survival, proliferation, and differentiation of adult-born cells in the hippocampus especially, through conserved stimuli-response mechanisms like the JNKs, which have been described as regulators of adult neurogenesis. In the present review, the JNK pathway and their control of adult hippocampal neurogenesis is described, evidencing the critical role of JNK1 in this process.