A population-based cohort study focusing on bladder, bowel and sexual dysfunction in MS-patients was performed. The total cohort under study comprised 209 patients. The duration of the disease was nine to 19 years. A total of 57.5% reported some to major bladder dysfunction. The corresponding figures of bowel and sexual dysfunction were 41.3% and 51% respectively. The dysfunction increased with higher age, higher age at onset of MS, duration and course of the disease. The most unfavourable course of the disease was the relapsing remittent secondary progressive form, where almost 70% became worse during an eight year's observation period, in contrast to patients with the relapsing remittent form, where less than 30% became worse. The study shows that a high number of MS patients is in need of a neuro-urological work-up, and that effort should be made to prevent or delay a secondary progressive course of the disease.