Many multiple sclerosis patients show cognitive decline, although no definite correlation between brain demyelination at MRI and neuropsychological performance has been found so far. We submitted a group of nine relapsing-remitting, mildly disabled patients to both serial gadolinium-DTPA enhanced MRI and neuropsychological evaluation in a follow up period of three months. Despite the great variability in acute lesions' load, no overall decline in test, performance was found. Furthermore, in selected cases whose test scores declined at follow up, no concordance with the new lesion load was found.