The present investigation assessed self-esteem effects on biological and subjective chronic stress measures, including cardiovascular parameters, health indicators, and mood. Moderators were examined, including vagal tone and social identity. High self-esteem was associated with higher baseline positivity, lower baseline negativity, and lower subjective stress across numerous domains including: city stress, chaos at home, and perceived stress (all p<.05). Vagal tone moderated the relationship between self-esteem and the chronic stress measure: hair cortisol (p<.05). The high self-esteem group showed lower cortisol, particularly when coupled with high vagal tone. Individuals with low vagal tone had the highest cortisol; for those individuals, high self-esteem does not appear to buffer this relationship. Vagal tone also moderated the relationship between self-esteem and resting heart rate (p<.05). Individuals with low vagal tone showed higher resting heart rate and high self-esteem did not appear to buffer this effect. Social identity, specifically positive race/ethnic identity, moderated the relationship between self-esteem and waist-to-hip ratio (WHR). Specifically, individuals with low self-esteem and low social identity showed the highest WHR. For those with low social identity and high self-esteem, however, WHR was decreased. These findings indicate that high self-esteem may be related to health, mood, and lower subjective stress. High self-esteem may not be sufficient, however, to buffer physiological indicators of chronic stress in individuals with low vagal tone. Additionally, personal self-esteem may more strongly influence health in individuals who do not have strong social identity. Future directions include investigating psychosocial factors that increase vagal tone to improve mood and well-being.​