In an effort to expand research on curiosity, we elaborate on a theoretical model that informs research on the design of a new measure and the nomological network of curiosity. Curiosity was conceptualized as a positive emotional-motivational system associated with the recognition, pursuit, and self-regulation of novelty and challenge. Using 5 independent samples, we developed the Curiosity and Exploration Inventory (CEI) comprising 2 dimensions: exploration (appetitive strivings for novelty and challenge) and absorption (full engagement in specific activities). The CEI has good psychometric properties, is relatively unaffected by socially desirable responding, is relatively independent from positive affect, and has a nomological network consistent with our theoretical framework. Predicated on our personal growth facilitation model, we discuss the potential role of curiosity in advancing understanding of various psychological phenomena.