Background: Multiple sclerosis (MS) is an inflammatory and demyelinating disease of central nervous system (CNS). The aim of the present study was to determine the type and the frequency of initial presenting symptoms in patients with MS and their relation with demographic characteristics in Babol, northern Iran.

 Methods: All patients of this study were recruited over a ten year period from 2002 to 2012 from single neurologic clinic. Diagnosis of MS was confirmed according to the McDonald criteria, demographic and clinical features Then, all the clinical findings and demographic variables including: age, sex, marital status, age at onset, education, place of residence, disease duration, initiation pattern of disease have been collected. Expanded Disability Status Scale (EDSS) was used for the evaluation of disability at the onset of disease. Data analysis was performed by chi-square test.

 Results: A total of 263 consecutive MS patients with the age range of 17 to 61 yr were examined. Optic neuritis was the most prevalent initial presenting symptom in 123 (46.8%) patients followed by sensory disturbances as the second common presenting symptom of MS. Significant difference was found between patients with or without optic neuritis and the onset age of the disease and EDSS (p<0.001). The mean EDSS score at the time of initial presentation was 1.67±0.77.

 Conclusion: The findings of this study indicated that optic neuritis is the most prevalent initial presentation of MS in the geographic region of northern Iran. In patients less than 30 years, development of visual disturbances justifies neurologic examination.