We report our experience in long-term treatment of relapsing remitting multiple sclerosis patients with natalizumab (N). In November 2009 we evaluated 141 patients (126 AIFA criterion A, 15 AIFA criterion B). We paid particular attention to the treatment period and the patients follow-up; during the whole therapeutic program, they undergone to clinical and radiological evaluation for every 3 months. The compliance was optimal and we found no significant side effects. 26 patients completed the 24 monthly doses. After 24 months 51% of patients were free from disease activity. We found a reduction in relapses and EDSS, moreover the clinical improvement was also confirmed by radiological examinations. Our results show that the best therapeutic results are achieved by early initiation of treatment.