Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease of the central nervous system occurring in genetically susceptible individuals. T and B lymphocytes are thought to be important in the pathogenesis of MS. Among the unmet needs in MS therapeutics are agents with improved efficacy and safety profiles and improved routes of administration. Cladribine, which is a preferential lymphocyte-depleting therapy, has the potential to be the first oral agent available for the treatment of relapsing forms of MS. This oral formulation is administered through intermittent, once-daily dosing to treat relapsing forms of MS. Cladribine as a parenteral formulation has extensive clinical experience for other disease states including hematologic malignancies and relapsing and progressive forms of MS. Cladribine tablets now are undergoing phase III development for the treatment of relapsing forms of MS. With the advent of new MS agents such as cladribine tablets, nurses will be critical in monitoring these new therapies.