A patient with recurrent-remittent multiple sclerosis associated with neurofibromatosis type I is described. The case is interesting for two reasons: 1) the difficulty of evaluating MRI findings, since both entities involve similar anomalies and 2) the relation between the two entities, according to evidence from recent genetic studies showing that the myelin protein gene associated to oligodendrocytes is part of an intron of the neurofibromatosis-1 gene of chromosome 17.