We present a case with diagnosis of multiple sclerosis done on clinical criteria and proved by autopsy. The morphological aspects of the lesions are well known and often related in the literature. Our objective is to describe the first necropsy among 30500 done at Santa Casa de São Paulo in a patient with the disease. The morphological aspects in the CNS with the characteristic plaques in different grades of activity and the detection of immunoglobulins in these plaques confirm the pathogenic hypothesis about a disease immunologically mediated.