For determining the prevalence of multiple sclerosis (MS) in Germany, the outcomes of several epidemiological studies are available. If these rates are transferred to Germany as a whole, figures result of 67,000 to 138,000 MS patients in all. The differing prevalence rates may be caused by various problems in finding patients, the epidemiological area, and different population structures. To avoid these difficulties, a new approach for calculating the number of patients with diagnosed MS was chosen based on representative samples taken from the groups of physicians involved in MS treatment. The disadvantage of this approach is that it does not allow any questioning of the diagnosis. Projecting the results in this way and their subsequent compilation--taking "double treatments" into consideration--showed a total of 122,000 patients with diagnosed multiple sclerosis in Germany. This figure corresponds to a prevalence rate of 149.1 per 100,000 inhabitants and is within the range found by Poser et al. [19]: 127 per 100,000 excluding the diagnostic category "possible multiple sclerosis" and 170 per 100,000 including it.