Magnetic-resonance imaging (MRI) is considered to be the most informative non-invasive method in diagnosis, differential diagnosis and estimation of activity of multiple sclerosis (MS). MRI data of 270 patients with clinically and laboratory definite MS were analyzed to assess diagnostic MRI-criteria for MS, MRI presentations at the time of first clinical manifestation of the disease, neuroimaging patterns in children and elderly persons with MS. The MRI variants of MS are substantiated. Neuroimaging data of cervical spinal cord in 28 patients with MS are presented in parallel with corresponding clinical data. The most typical patterns are singled out. The data of brain 1H-magnetic-resonance spectroscopy (MRS) in 20 patients with MS and 8 patients with inflammatory and vascular disorders were analyzed to reveal biochemical distinction between MS and non-MS lesions as well as changes in normal appearing white matter in MS. The differential-diagnostic value of MRS is limited although decreased N-acetyl-aspartate peak is characteristic for MS lesions and in some cases in normal appearing white matter in primary-progressive MS.