The common marmoset Callithrix jacchus is a primate phylogenetically close to humans which, when immunized with myelin proteins, is susceptible to a form of experimental autoimmune encephalomyelitis (EAE) that resembles multiple sclerosis (MS). Neuropathological features of marmoset EAE, including inflammation, demyelination and axonal injury, are strikingly similar to findings in the human disease and are the final result of a joint autoimmune attack by myelin-specific T and B cells. The molecular and functional similarity of the marmoset immune system, together with the availability of diagnostic tools that can be used in humans (such as magnetic resonance imaging), makes the marmoset EAE a unique model with which to evaluate the safety and efficacy of therapeutic strategies for the treatment of MS.