Abstract Background The myths of aging provide a partial explanation for why older people have not been primary targets for health promotion and disease-prevention programs. Accelerated population aging signals an urgent need for increased attention to health promotion and disease-prevention interventions across the entire life course. Objective The purpose of this article is to review what is known about: (1) the prevalence and nature of ageist stereotypes; (2) the varied ways in which ageist stereotypes are harmful to health, functioning, and well-being; and (3) strategies for effective communication with older adults around lifestyle issues, with particular emphasis on physical activity. Method This article reviews literature on current myths and reality of aging in the context of designing health promotion programs for older adults. Strategies for combating ageist stereotypes are based on a multilevel view of determinants of health and aging. Conclusions Ageist stereotypes are pervasive in U.S. society and harmful to older adults' psychological well-being, physical and cognitive functioning, and survival. Concrete strategies for communicating with older adults can increase the effectiveness of health promotion programs. Strategies for combating ageism and creating a healthier society must address all segments of society, and include educational and media campaigns, an expansion of current research foci, greater sensitivity from care providers, more opportunities for intergenerational linkages, the design of productive roles for older adults, a retrofit of the built environment, and intensified and collaborative action from both the public and private sectors.