Despite considerable research demonstrating associations of conscientiousness and neuroticism with health-related behavior, our understanding of how and why these traits are related to lifestyle is limited. This study examined the social regulation of health behavior in a probability sample of 509 household residents who completed a Random Digit Dial (RDD) telephone survey. Results suggest that the social regulation of health behavior experienced by highly conscientious individuals has more to do with their own internalized notions of responsibility and obligation to others than to specific actions by others aimed at influencing their health habits. In contrast, individuals with higher neuroticism experience more overt attempts by others to influence their health habits but have more negative affective and behavioral responses to these social influence attempts. Findings suggest that elucidating the distinct social influence processes that operate for conscientiousness and neuroticism may further understanding of how these traits are related to health behaviors and status.