Background Urinary dysfunction is a common symptom during the course of multiple sclerosis (MS). Long-term follow-up of the natural history of bladder dysfunction in MS has been seldom addressed. Objective To identify the type and the course of voiding dysfunction in MS patients in relation to the urodynamic changes of the lower urinary tract (LUT) Subjects and methods An observational prospective study including 120 MS patients with urinary dysfunction rated by the American Urological Association (AUA) symptoms questionnaire and assessed by urodynamic studies and followed for 1 year. Results Irritative symptoms were the most frequently encountered symptoms (90%), whereas overactive bladder was recorded by urodynamic studies in 35% of subjects. Urinary symptoms severity score was higher in patients with initial urodynamic abnormalities by the end of the 1-year follow-up period ( P < 0.001). A statistically significant relationship was found between urinary symptoms severity score and each of expanded disability status scale (EDSS) and urodynamic pattern of abnormalities ( P < 0.01). Conclusion Irritative symptoms and overactive bladder seem to be the most frequent urinary dysfunction in MS patients. Urinary symptoms are related to the degree of disability. The initial urodynamic abnormalities are associated with worse urinary dysfunction outcome after 1 year.