Throughout the last three decades the number of patients with pacemakers has increased. Registers of pacemakers and pacemaker patients have been established to monitor, for example, the battery life expectancy and patient data. We have analyzed the registry for Fyn county, Denmark, which includes data on incidence, prevalence, and mortality rates among patients with pacemakers during the period from 1964 to 1990. The analyses show that the prevalence rate is steadily increasing as a result of a combination of an increasing incidence rate and a stable mortality rate among the pacemaker patients. Based on the development in the first almost 30 years of pacemaker implantations, two trends of the future prevalence of pacemaker patients are projected. Provided constant mortality rates and expected incidence rates of 300 per million person years and 350 per million person years, respectively, the prevalence will reach a plateau of 2.7 per 1,000 persons and 3.1 per 1,000 persons, respectively, within the next 25 years.