The proportion of older individuals in the population is increasing. This study aimed to estimate the incidence and lifetime risk (LTR) of Parkinson disease (PD) in a large (n=21,970) cohort of men. Since age is currently the strongest risk factor for PD, that might seem strange but this study looks at whether incidence continues to increase after age 80 years. The crude incidence rate of PD was 121 cases/100,000 person-years with age-specific incidence rates increasing sharply beginning at age 60 years, peaked in those aged 85–89 years, and declined beginning at age 90 years. However, whether the subsequent decline represented a true decrease in risk remains to be established as incidence studies that do not adjust for competing risks of death may overestimate the true risk of PD in the elderly.