Multiple sclerosis (MS) is typically a disease of young adults. Childhood MS can be defined in patients under 18 years of age, although some authors set the limit un-der the age of 16 formerly known as "early-onset multiple sclerosis" or "juvenile multiple sclerosis", seen in 3-5% of all MS patients. Nowadays, owing to ever-evolving, better diagnostic tools and well-traced, strictly defined diagnostic criteria, childhood MS is showing an increasing incidence worldwide (0.05-2.85/100 000). MS is characterized by recurrent episodes of the central nervous system with demyelination separated in space and time. In childhood almost exclusively the relapsing-remitting (RR) type of MS occurs. Based on experience in adults, the goal in the pediatric population is also the early diagnosis, to initiate adequate DMT as soon as possible and to achieve symptom relief and good quality of life. Based on efficacy and safety studies in the adult population, inter-feron β-1a and glatiramer acetate were first approved by the FDA and EMA for the treatment of childhood MS also. The increased relapse rate and rapid progression of childhood MS and unfavorable therapeutic response to nearly 45% of the first DMT necessitated the testing of more effective and second-line drugs in the population under 18 years of age (PARADIGMS, CONNECT). Although natalizumab was reported to be effective and well-tolerated in highly active RRMS in childhood, evidence based studies were not yet available when our patients' treatment started. In this article, we report on the successful treatment of three active RRMS patients with individually authorized off-label use of natalizumab.