New insights into the biology of neural stem cells (NSCs) have raised expectations for their use in the treatment of neurologic diseases. Originally, NSC transplantation was proposed as a means of replacing cells in central nervous system diseases that result in cell loss. However, recent data regarding their beneficial effects in various animal models of neurologic diseases indicate that transplanted NSCs may also attenuate deleterious inflammation, protect the central nervous system from degeneration, and enhance endogenous recovery processes. Herein, we review recent developments and future prospects of NSC therapy in neurologic diseases.