The observation of many multiple sclerosis (MS) cases among shoe and leather workers prompted a survey of the risk of MS in this working population. Eighty-one patients with definite or probable MS alive in Florence on May 1st 1976 were interviewed regarding their occupation at onset of the disease. Five of the 41 patients working at the time had worked in shoe a leather factories. The relative risk for these workers was 4.87 compared to the general populations and 4.91 compared to the active population, both results being significantly different from one. This survey indicates an increased risk of MS among shoe and leather workers. Organic solvents, contained in large quantities in the glues used, may be involved in the pathogenic mechanism through a possible interference with the immune system.