Multiple sclerosis (MS) is a demyelinating disease of the central nervous system in which immune mechanisms appear to be an important component of the pathophysiology. Although the clinical manifestations are variable, a subset of patients develops a progressive clinical course associated with marked neurologic impairment and significant morbidity. BMT has been proposed as treatment for such patients based on preclinical data as well as clinical observations in other autoimmune diseases. We report clinical and MRI findings in an MS patient, later diagnosed with CML, and treated with an allogeneic BMT.