This study examines the associations among attachment styles, hardiness, and mental health in intensive real-life stress. Four hundred and thirty-four young Israeli men, candidates for service in an elite combat unit, were assessed towards the end of a highly demanding screening process. Secure attachment style was positively associated with overall hardiness, commitment, and control, whereas avoidant and ambivalent attachment styles were negatively associated with these variables. In addition, a secure attachment style, and overall hardiness, commitment, and control were positively associated with mental health and well-being, and negatively associated with distress and general psychiatric symptomatology, whereas avoidant and ambivalent styles were inversely related to mental health and well-being and positively related to distress and general psychiatric symptomatology. Regression models testing the relationship between attachment, hardiness, and mental health suggest that both attachment and hardiness are predictors of mental health in real-life stress. Findings are discussed with respect to theories of both attachment and hardiness.