Neural stem cells (NSCs) play a central role in the nervous system development and regeneration. In the adult mammalian brain, most NSCs remain in a quiescent state, but they can exit quiescence and become active, leading to the generation of new neurons. Maintaining a balance between NSC quiescence and activation is important for adult neurogenesis. Similar to their mammalian counterparts, Drosophila NSCs transition between quiescence and reactivation. This review summarizes the latest insights into the molecular processes driving the reactivation of quiescent NSCs in the Drosophila larval brain. We focus on recent advances in stem cell niches, cytoskeletal proteins, and both transcriptional and posttranslational regulations during NSC reactivation, as well as a new regeneration model in the Drosophila brain.