The aim of the study was to describe the atrophy of the thalamus in young patients with active relapsing multiple sclerosis (MS) treated with cerebrolysin. Eighteen MS patients (mean age 20.10±0.45 years) with disease onset in childhood or adolescence were studied. Neurological examination using the EDSS, neuropsychological testing and MRI were used. At baseline, MRI revealed the hypotrophy of the thalamus that was not correlated with the performance on neuropsychological tests. After treatment with cerebrolysin, there was the decrease in the level of atrophy that suggested the neuroprotective effect of this drug. This effect was more prominent in younger patients with the high frequency of previous relapses.