Expressing our innermost thoughts and feelings is critical to the development of intimacy (Reis & Shaver, 1988), but also risks negative evaluation and rejection. Past research suggests that people with high self-esteem are more expressive and self-disclosing because they trust that others care for them and will not reject them (Gaucher et al., 2012). However, feeling good about oneself may not always be enough; disclosure may also depend on how we feel about other people. Drawing on the principles of risk regulation theory (Murray et al., 2006), we propose that agreeableness—a trait that refers to the positivity of interpersonal motivations and behaviors—is a key determinant of trust in a partner’s caring and responsiveness, and may work in conjunction with self-esteem to predict disclosure. We examined this possibility by exploring how both self-esteem and agreeableness predict a particularly risky and intimate form of self-disclosure, the disclosure of emotional distress. In 6 studies using correlational, partner-report, and experimental methods, we demonstrate that self-esteem and agreeableness interact to predict disclosure: People who are high in both self-esteem and agreeableness show higher emotional disclosure. We also found evidence that trust mediates this effect. People high in self-esteem and agreeableness are most self-revealing, it seems, because they are especially trusting of their partners’ caring. Self-esteem and agreeableness were particularly important for the disclosure of vulnerable emotions (i.e., sadness; Study 5) and disclosures that were especially risky (Study 6). These findings illustrate how dispositional variables can work together to explain behavior in close relationships.