In this retrospective study, the results from investigations (MRI, evoked potentials, alkaline oligoclonal bands [OBs] in CSF) in 94 patients with clinical suspicion of demyelinative disease were evaluated to assess their impact on diagnosis. Forty-three patients were diagnosed as having definite MS, 10 probable MS, and 9 possible MS. MRI findings strongly suggestive of MS were evident in 52/62 (84%) patients, while 47/62 (76%) patients demonstrated OBs in their CSF. In 63% of patients both abnormalities were present. Patients with no OBs in their CSF were on the average older, were more often male, had experienced their first symptoms at a later age, and suffered more often from the chronic-progressive form of the disease than those with a positive CSF finding.