This study reports on a 4-year follow-up of cognitive functioning in 33 MS patients and 18 healthy control subjects. As a group, and in agreement with the results in the previous assessment. MS patients have significantly weaker performances than controls in motor speed, reaction time, learning tasks, reading aloud and figure copying. Tasks addressing visuospatial problem solving, behavioural flexibility, and linguistic aspects of oral and written communication do not distinguish between the two groups. Influence of impaired movement is acknowledged in performances utilising speech and reading under instructions of speed, and in figure copying. Cognition per sé remained undisturbed in 25 patients (76%). A uniform MS-related development of cognitive deficits could not be identified, improvement, stability and further deterioration being found at reassessment.