Alzheimer's disease (AD) is considered a leading cause of death but few studies have examined the contribution of AD to mortality based on followup of representative cohorts. In a fifteen-year prospective epidemiological study of 1670 adults aged 65+ years a rural US community, we found that AD was responsible for 4.9% of deaths in this elderly cohort. AD increased the risk of mortality by 40% in the cohort as a whole and in women but not in men. Mean (SD) duration of survival with AD was 5.9 (3.7) years, and longer with earlier age at onset. Death certificates of AD subjects were significantly more likely to list dementia/AD, other brain disorders, pneumonia, and dehydration; and significantly less likely to include cancer.