Public health nurses visited and followed up for more than one year 438 patients with Parkinson's disease living in Osaka. The follow-up period averaged 4.1 years, during which 71 deaths were observed. The patients were classified according to the degree of physical exercise they performed, and the ratios of observed to expected deaths were calculated. The exercising group showed the lowest ratio of 1.68 (1.45 for patients able to walk independently, and 1.89 for those could not) while all patients exhibited a ratio of 2.47. Multivariate analysis using Cox's proportional hazard model, adjusted for age, sex, walking ability and duration of disease at study entry, showed that, compared with the exercising group, the non-exercising patients had a hazard ratio of 1.83.