A patient with tumefactive multiple sclerosis (MS) initially presented at the age of 87 years; the revised diagnostic criteria from the International Panel on MS (2001) were fulfilled. Late-onset MS and tumefactive demyelinating lesions are discussed. This case suggests that MS can occur at any age. MS should be borne in mind for differential diagnosis if a brain tumor-like lesion with little mass effect and edema is found in an elderly patient.