Objective To ascertain the prevalence of anorectal dysfunction (ARD) in patients with multiple sclerosis (MS) and its relationship with MS clinical characteristics. Methods Prospective transversal study in 193 patients with MS. All patients fulfilled a protocol that included: demographic variables, clinical characteristics of MS and the presence of ARD and urinary dysfunction (UD). Results One hundred and ninety-three patients: 66.8% women, an average age of 42.8 (12.1) years; 67.8% of patients had relapsing-remitting MS, 21.2% a secondary progressive and 10.9% a primary progressive form. The average duration of MS was 10.7 (9.4) years and the EDSS 2.8 (2.3). ARD was present in 93 patients (48.2%), and UD in 50.2%. ARD associated to UD was present in 35.7% of cases. The univariate study revealed that patients with ARD were older (p Conclusion ARD is a highly prevalent disorder in MS. Female sex, EDSS and UD are independent predictors of ARD development.