Recent work has extended the idea of implicit self-theories to the realm of emotion to assess beliefs in the malleability of emotions. The current article expanded on prior measurement of emotion beliefs in a scale development project. Items were tested and revised over rounds of data collection with both students and nonstudent adult online participants. Exploratory and confirmatory factor analyses revealed a three-factor structure. The resulting scale, the Emotion and Regulation Beliefs Scale, assesses beliefs that emotions can hijack self-control, beliefs that emotion regulation is a worthwhile pursuit, and beliefs that emotions can constrain behavior. Preliminary findings suggest that the Emotion and Regulation Beliefs Scale has good internal consistency, is conceptually distinct from measures assessing individuals’ beliefs in their management of emotions and facets of emotional intelligence, and predicts clinically relevant outcomes even after controlling for an existing short measure of beliefs in emotion controllability.