In the U.S., there are persistent sex differences in health that cannot be wholly explained by biological sex. Agency (AG), communion (CM), unmitigated agency (UA), and unmitigated communion (UC) are personality traits that may help explain individuals' health behaviors. AG is a positive focus on the self characterized by fulfillment through accomplishment and independence; CM is a positive focus on others characterized by fulfillment through relationships. UA is a negative focus on the self characterized by hostility and arrogance; UC is a negative focus on others characterized by placing others' needs before one's own. The socialization of men and women into acquired sex roles, which can be measured using AG and CM constructs, may help explain sex-related health disparities. The purpose of this research was to determine if AG and CM constructs explain more variance than sex in selected health behaviors. In general, AG and CM were expected to predict positive health behaviors, while UA and UC were expected to predict negative health behaviors. A self-report, cross-sectional survey was conducted among 398 full-time undergraduate students from two universities. Survey items measured AG and CM constructs and health behaviors, which included fruit and vegetable consumption, high-fat food consumption, physical activity, tobacco use, alcohol use, condom use, and willingness to seek professional medical and counseling services. Multivariate regression analyses revealed that AG was a stronger predictor than sex for fruit and vegetable intake and physical activity, while UA was a stronger predictor than sex for alcohol use. CM was not a stronger predictor than sex for any health behaviors and UC did not predict any health behaviors. The AG and CM constructs did not predict any variance for willingness to seek treatment, tobacco use, or condom use. The results of this study provide some evidence to support the growing body of literature that has found value in distinguishing biological sex from socialized sex roles when explaining health behaviors. The results indicate that it should not be assumed that health differences between males and females are solely attributable to sex. Health promotion professionals may use these results as a guide for programming by focusing on sex roles instead of biological sex as a basis for understanding and changing health behaviors. This research shows that when applied to certain health behaviors, AG and CM constructs can explain more variance than biological sex and possibly lead to a more comprehensive understanding of health behaviors. Keyword(s): disease prevention/wellness, gender issues, health promotion