Protein arginine methylation is a post-translational modification catalyzed by the protein arginine methyltransferase (PRMT) family, which is highly conserved across species. PRMTs methylate histone and non-histone proteins, thereby regulating protein function, interactions, stability, and localization. These modifications play essential roles in gene expression, signal transduction, cell proliferation, apoptosis, and survival. Aberrant PRMT activity has been linked to various cancers, suggesting arginine methylation is crucial for biological functions in both health and disease, and may serve as a therapeutic target. Recent advances in tissue-specific gene knockout technology in mice have revealed the physiological roles of PRMTs in nervous system development and homeostasis. The mammalian central nervous system (CNS) develops through neural stem cell proliferation and differentiation into neurons and glial cells. This chapter provides an overview of arginine methylation, its biochemical mechanisms, and biological significance. We focus on how PRMTs regulate molecular networks essential for neural development and maintenance. Furthermore, we examine the pathological implications of dysregulated arginine methylation in neuronal disorders, including neurodegeneration, intellectual disabilities, and ALS, offering insights into its role in disease progression. Through this, we aim to clarify the critical functions of PRMTs in both normal and pathological CNS states.