Preventive health behavior is broadly defined to encompass a spectrum of actions that range from voluntary exposure to the risk of disease, injury, or death to active efforts at prevention or detection of disease. Data are presented to show that men, in our culture engage in more risk-taking behavior and take preventive measures less frequently than women, while women avoid risks and take preventive action, particularly when this action requires medical intervention. The literature review supports the hypothesis that these differences in behavior arise out of the socialization and adult role patterns that our society defines as appropriate for each sex. Women, in particular, are encouraged to define their problems in medical terms and to seek help for them within the medical care system.