The Canadian Study of Health and Aging (CSHA) is one of the largest epidemiologic studies of dementia conducted to date, with over 100 papers published or in press. The first (prevalence) phase data collection began in 1991, and the second (incidence) phase was completed in 1996. Publication of first and second phase data began in 1994 and 1998, respectively. The CSHA has contributed not only to our understanding of dementia, but also more broadly to the population health of elderly people. However, for those unfamiliar with the CSHA, gaining an understanding of the study's design and results has been difficult, due to the study's scope and complexity and necessarily brief descriptions of study methods in journal articles. Now, given the widespread availability of the data to the public at large and the research community, a comprehensive description of the study methods and data sets is desirable as a guide for potential users.