This article provides a brief outline of the development of men's health studies in the United States. Research on men's health is discussed within critical feminist theories that highlight the reciprocality of gender relations as well as power differences between men and women and among male subgroups. A relational theory of gender and health is used to identify both positive-gendered and negative-gendered health synergies that influence the health processes and outcomes of men and women. Several examples of gendered health synergies are presented to illustrate key concepts. Finally, some directions for future research and advocacy with reference to men's health are outlined.