The authors examined the relation between age-related maculopathy and Alzheimer's disease in the Rotterdam Study, a prospective population-based study in the Netherlands. From 1990 to mid-1993, subjects aged 75 years or older (n = 1,438) were screened for the presence of age-related maculopathy and Alzheimer's disease, and follow-up examinations were conducted from mid-1 993 to the end of 1994. Subjects with advanced age-related maculopathy at baseline showed an increased risk of incident Alzheimer's disease (relative risk = 2.1, 95% confidence interval: 1.1, 4.3; adjusted for age and gender), but this risk decreased after additional adjustment for smoking and atherosclerosis (relative risk = 1.5, 95% confidence interval: 0.6, 3.5). These findings suggest that the neuronal degeneration occurring in age-related maculopathy and Alzheimer's disease may, to some extent, have a common pathogenesis.