Based on data from the 1996/1997 (institutional component) and 1998/1999 (household component) National Population Health Survey, seniors were major consumers of prescription medications, over-the-counter (OTC) products, and natural and alternative medicines. Almost all (97%) seniors living in long-term health care institutions were current medication users (medication use in the two days before their interview), as were 76% of those living in private households. Over half (53%) of seniors in institutions and 13% of those in private households used multiple medications (currently taking five or more different medications). Both medication and multiple medication use were associated with morbidity. Medications for the nervous system, the alimentary tract and metabolism, and the cardiovascular system were reported most frequently. Among seniors in institutions, those with Alzheimer's disease were less likely to take multiple medication than were those without this condition.