Pediatric clinical trials were not required for new therapeutics. As a result, children were often prescribed medications off-label based on data from adult studies, or were unable to receive potentially beneficial therapies because of a lack of official approval for use in the pediatric population. As this was deemed unethical and detrimental in some cases, legislation was recently approved that now mandates pediatric studies for all new therapeutics. As pediatric MS trials are now being designed, challenges regarding their feasibility have been identified. These include sample size limitations, determination of appropriate study endpoints and pediatric MS-specific outcomes, and fear about the unknown impact of these new agents on the maturing immune, reproductive, and central nervous system.