Multiple sclerosis (MS) is the most common inflammatory demyelinating disorder of the human CNS, affecting an estimated 2.5 million people in the world. Until the 1990s, treatment was mainly symptomatic, but a new era began with the introduction of disease-modifying therapy that seems to alter the natural course of MS. Current drugs include three interferons (IFNs): IFN-beta1a (Avonex intramuscular; Biogen, Cambridge, USA; Rebif subcutaneous; Serono, Geneva, Switzerland), IFN-beta1b (Betaseron subcutaneous; Schering, Berlin, Germany) and glatiramer acetate (Copaxone subcutaneous; Teva, Petach Tikva, Israel). Ongoing research targeting a variety of mechanisms and processes means there is much promise for the future treatment of MS.