Background: The use of unconventional therapies is growing in western countries. Few studies on their frequency and rationale among multiple sclerosis (MS) patients have been carried out in Europe. Objective: To assess the frequency of use of unconventional therapies among MS patients and to explore associated clinical variables. Methods: Structured questionnaires were given to 380 consecutive patients seen at two hospital-based MS clinics in Barcelona. C linical and demographical data were recorded at the same time. The questionnaire inquired about demographical features, educatio n, income, use of unconventional therapies for MS and satisfaction with conventional medicine both in general and specifically in MS. Results: The response rate was 50.78%. Forty-one per cent of patients admitted using unconventional therapies during the previous year. Low levels of satisfaction with conventional medicine in general and for MS, and higher Expanded Disability Status Scale (EDSS) scores (EDSS mean: 4.43 in users versus 3.48 in nonusers) were significantly associated with use of unconventional therapies. Conclusion: Use of unconventional therapies is not rare among MS patients, and it is associated with high disability levels and dissatisfaction with conventional medicine.