Objectives: The aim of this paper was to assess the effects of aerobic training on the quality of life and fatigue in patients with multiple sclerosis. Material and methods: A total of 53 patients with known multiple sclerosis (ICD G35.0) who began a standard 4-week rehabilitation programme were included in the study. Patients were divided into two groups: AT (aerobic training) patients (n = 21), who additionally underwent training on a lower limb cycle ergometer (three 10-minute sessions per day with an hour interval), and non-AT group of patients (n = 32). Life quality assessment based on the WHOQOL-BREF scale (World Health Organization Quality of Life), an assessment of motor impairment based on the Expanded Disability Status Scale by Kurtzke (EDSS) and an assessment of the severity of fatigue using the Fatigue Severity Scale (FSS) were performed at baseline and after four weeks. Results: After completing rehabilitation programmes, an improvement in the quality of life was observed both in AT and non-AT group. However, a more significant improvement in the two evaluated aspects, physical (p = 0.001 vs. 0.01) and psychological (p = 0.001 vs. 0.05), was observed in the AT group. However, no improvement in social terms was observed. There was also a reduction in the severity of fatigue (0.03 for AT group vs. 0.15 for non-AT group). There was no statistically significant improvement in the EDSS score in any of the groups. Conclusions: Aerobic training has beneficial effects on the quality of life and the severity of fatigue in patients with multiple sclerosis.