Introduction. In Peru up to recent years multiple sclerosis (MS) was considered a very rare disorder. Aim. To report clinical, epidemiological and ancillary test results of an MS cases series. Patients and methods. Description of a retrospective cohort of 55 patients studied in HNCH and a private neurological center in Lima between 1993-2004. Clinical records, laboratory and MRI tests were reviewed with Mc Donald's criteria. Results. There were 55 cases (36 women). Mean age was forty. 65% were born in Lima, 27% have foreign ancestor up to third generation. 42 cases were definite MS and 13 possible MS. The most frequent form of MS was RRMS (49.1%). Early symptoms were optic neuritis, motor and sensitive complaints; in the follow up cerebelar symptoms, increase of motor compromise and sphincteric disturbance were showed. Brain and spine MRI were positive in 27 cases and 17 cases respectively. VEP were abnormal in 53% of cases, just one case had cerebrospinal fluid (CSF) compatible with MS. Mode of EDSS was 6.5. Immunomodulators were used in 30% of cases. Survival at 10 and 20 years of disease were 87% and 45% respectively. Conclusion. Our study shows than optic neuritis is an important early symptom and CSF study is commonly negative in patients with MS. Survival is shorter than other reports. Other features resembled previous international reports. To have foreign ancestors could be a risk factor for MS in this group. © 2005, Revista de Neurología.