The numbers of patients aged 35 years or more with hypertension, ischemic heart disease, and cerebrovascular disease 15 years from now were estimated. First, the numbers of patients with these diseases in 1984, 1987, 1990, and 1993 were calculated by age and sex using data from the National Patient Surveys conducted by the Ministry of Health and Welfare. Then, population prevalence for calendar years 1996, 1999, 2002, 2005, and 2008 were estimated based on the past data using linear regression models. Finally, the total numbers of patients were calculated from the estimated prevalence multiplied by the estimated population figure of the national government. The numbers of patients with hypertension will decrease in younger age classes but increase in older age classes; the total number of all patients, therefore, will increase. While the number of patients with ischemic heart disease in males is estimated to increase, that in females will level off. The number of cerebrovascular disease patients in each age and sex group will grow larger.