Introduction: Neuroplasticity is the function of the central nervous system that allows structural and functional reorganisation in response to external and internal factors. It is a crucial aspect that allows for the restoration of motor functions in people with limited brain damage. Patients with multiple sclerosis may obtain a special benefit from activities that support brain neuroplasticity. In order to stimulate neuroplasticity, several attempts were made to identify neuroplasticity-influencing factors. Aim: The objective of the study was to measure the effect of aerobic training on plasma neurotrophin levels that are potentially responsible for the brain plasticity phenomenon in patients with multiple sclerosis. Materials and methods: The study was conducted on a group of 22 patients with multiple sclerosis remaining in the drug programs of the National Health Fund. The study group underwent a 4-week rehabilitation scheme that consisted of training on a horizontal ergometer twice a day for 15 minutes 6 days a week, whereas the control group did not participate in any form of training. The plasma levels of neurotrophins (BDNF, PDGF, NGF, GDNF) and fractalkine (chemokine CX3CL1) were tested in all patients, the patients were assessed in the motor disability scale, the cognitive function screening and Beck depression inventory at the beginning of the study and after 4 weeks of rehabilitation. Results: The study showed no statistically significant difference in the levels of neurotrophins assessed before and after 4 weeks of aerobic training. A significant improvement in the clinical condition evaluated with the Expanded Disability Status Scale (EDSS) and Mini-Mental State Examination (MMSE) was observed in patients from the study group. Conclusion: Further studies on larger groups and with more homogenous participants are necessary to gain more insights into this aspect.