Alzheimer's disease is not typically included on the list of important women's health issues. Yet Alzheimer's disease is indeed a women's disease. Not only do more women than men have Alzheimer's disease, but women also provide a disproportionate amount of the informal community care for people with the disease. The prevalence of Alzheimer's disease increases dramatically with age and is highest among those 85 years of age and older. Women make up 72% of the US population over age 85 and, therefore, are the group most affected by the disease. By the year 2050, the number of people with Alzheimer's disease will more than double from approximately 4 million to 10 million, and 70% of these people will be age 85 or older. Although the symptoms and course of Alzheimer's disease may be similar in women and men, social and economic factors may produce a greater burden of disease among women, particularly with respect to the types and quality of health care services they receive, because women generally have the most limited social and financial resources. As the population ages, typical patients with Alzheimer's disease will be much older, frailer, and will have more functional impairments and chronic diseases than the patients most physicians see today. Future research needs to focus on identifying modifiable risk factors and effective treatments for Alzheimer's disease, and on determining the appropriate types of community-based and institutional services required to care for those with the illness as well as their families.