Most people hold both positive and negative beliefs about themselves. The way individuals organize, or structure, these beliefs in their self-concepts can facilitate realistic acceptance and confrontation of negative self-beliefs (integration), or defensive avoidance and denial of negative self-beliefs (compartmentalization). This article focuses on the distinction between individuals with a realistic, secure self and a defensive, fragile self. We present evidence that compartmentalization is associated with several indicators of a defensive, fragile self, such as contingent self-esteem and unstable self-evaluations. In addition, individuals with this structure are likely to engage in defensive processes that enhance or protect the self. This model of self-organization can provide a window on the defensive self, allowing researchers to observe the process by which individuals think about and defensively avoid negative self-beliefs.