Multiple sclerosis (MS) is the most common inflammatory disease of human central nervous system (CNS), which is characterized by inflammatory demyelination and neuroaxonal injury/loss. The majority of MS patients are diagnosed in early- to mid-adulthood; however, the onset of MS in childhood is being increasingly recognized. Although adults and children share important aspects of the disease, several features including course of the disease and a broader differential diagnosis are unique to children. This chapter summarizes recent insights and emphasizes that children with MS should be started on immunomodulatory therapies early in order to prevent future disability.