This review focuses on the role of CD56bright natural killer (NK) cells in neurodegenerative diseases, such as multiple sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). CD56bright NK cells are potent cytokine secretors and are considered more immunoregulatory compared to their cytotoxic CD56dim counterparts. The review explores the mechanisms by which CD56bright NK cells enter the central nervous system (CNS) and their potential immunoregulatory functions. It also discusses the impact of aging on NK cell characteristics and the role of CD56bright NK cells in neurodegenerative diseases. The review highlights the contradictory findings regarding the role of NK cells in MS, with some studies suggesting a beneficial effect of CD56bright NK cells, while others indicate a detrimental role. The impact of therapies, such as daclizumab, on CD56bright NK cells is also discussed. Overall, the review aims to provide a comprehensive overview of the role of CD56bright NK cells in neurodegenerative diseases and their potential implications for future therapeutic interventions.This review focuses on the role of CD56bright natural killer (NK) cells in neurodegenerative diseases, such as multiple sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). CD56bright NK cells are potent cytokine secretors and are considered more immunoregulatory compared to their cytotoxic CD56dim counterparts. The review explores the mechanisms by which CD56bright NK cells enter the central nervous system (CNS) and their potential immunoregulatory functions. It also discusses the impact of aging on NK cell characteristics and the role of CD56bright NK cells in neurodegenerative diseases. The review highlights the contradictory findings regarding the role of NK cells in MS, with some studies suggesting a beneficial effect of CD56bright NK cells, while others indicate a detrimental role. The impact of therapies, such as daclizumab, on CD56bright NK cells is also discussed. Overall, the review aims to provide a comprehensive overview of the role of CD56bright NK cells in neurodegenerative diseases and their potential implications for future therapeutic interventions.