Previous studies have shown the Fennoscandian region to be a high-risk area for multiple sclerosis (MS). In order to investigate the distribution of MS in Sweden, mortality (1952-1992) and disability pensioning statistics (1971-1994) were studied. A total of 11,414 cases with a disability pension and 5,421 cases with MS on their death certificate were analysed according to county and time period and the results were compared with the mortality figures for amyotrophic lateral sclerosis (ALS) and disability pensioning statistics for Parkinson's disease. We found increasing rates of both MS mortality and disability pensioning. Disability pensioning correlated well with mortality 10 years later (r = 0.42, p = 0.04). We also found a marked geographical variation. Värmland county had the highest mortality, with 14 out of its 16 municipalities having higher rates than the national mean. Unexpectedly, we found a high correlation between mortality due to MS and ALS (r = 0.60, p = 0.002).