Seventy patients with multiple sclerosis (according to Poser's criteria) were clinically assessed and examined with MRI, multimodal evoked potentials (VEP, AEP, SSEP) and CSF analysis (transformed lymphocytes, IgG-Index, oligoclonal banding). In relation to the clinical criteria of McAlpine 40 patients had possible, 16 patients probable and 14 patients definite MS. 81% of the patients (73% possible MS, 94% probable MS, 93% definite MS) had multiple white matter lesions detected by MRI, 79% (78% possible MS, 94% probable MS, 64% definite MS) had an abnormal CSF profile and 67% (60% possible MS, 75% probable MS, 79% definite MS) abnormal results in multimodal EP testing. Of the patients who experienced only one attack (n = 40) 78% had multiple lesions on MRI, 88% had abnormal CSF-findings and 60% had pathologic EPs. Patients with two or more attacks showed in 87% multiple lesions on MRI, in 77% abnormal EPs and in 70% abnormal CSF findings. The number of abnormal MRI and EPs increases with the duration of the disease. 13 patients with a normal MRI were discussed separately. MRI is the most sensitive method in detecting the spatial pattern of disseminated lesions. To monitor the dissemination over time a careful clinical follow-up is still mandatory.