Chronic disease is often connected with multiple loss experiences and demands the activation of coping resources to regain or compensate for them or to prevent further losses. Generalized personal resources such as hardiness or optimistic self-beliefs are expected to function as strong stress buffers as long as they are not object of loss themselves. But how do personal resources work? Normally, differences in self-regulation abilities and corresponding coping behaviors are taken into account to explain the effects of personality in stress and illness. Based on an integrative theoretical approach, self-regulation competence is introduced as a new personality construct, covering "volitional competence", "coping competence", and different kinds of "habitual self-control" (e. g. "motivation control"). In an extensive longitudinal study on heart patients undergoing cardiac surgery the impact of self-regulation competence on coping success is examined. The moderating effect of this personal resource variable on the stress-distress-relationship as well as the mediating role of coping behaviors in dealing with the illness are highlighted and the meaning of volitional components on health behaviors are analysed and discussed.