The aim of this paper is to review the quantitative methods used for assessing neurological status in multiple sclerosis patients. The Expanded Disability Status Scale (EDSS) is the most wide used. Its psychometric properties, validity, and inter- and intra-rater reliability are modest and responsiveness is weak. Similar results are obtained with the other scales used. The recently developed Multiple Sclerosis Functional Composite (MSFC) scale for clinical trials satisfies this requirement, but is not suitable for individual evaluation. There is no scale in French for assessment of cognitive disturbances and only one, the SEP-90, for quality of life. Brain and spinal cord abnormalities with conventional magnetic resonance imaging parameters (T1, T2-weighted and gadolinium enhanced images) have a weak relationship with disability. New magnetic resonance techniques (magnetic resonance spectroscopy and magnetized transfer imaging) would be more sensitive and should be further investigated.