The broad array of economic and cultural diversity in the U.S. population correlates with and impacts on the study of behavioral aspects of health. The purpose of this article was to provide a selective overview of behavioral medicine research on sociodemographically diverse populations, with a focus on ethnicity, gender, and socioeconomic status. Suggestions are provided with regard to methodological refinement of research and insights into possible future directions in behavioral medicine research on ethnically and economically diverse populations.