This article presents the development and validation of two new measures of psychological well-being: the Comprehensive Inventory of Thinking (CIT), and the Brief Inventory of Thinking (BIT). These measures were developed to a) measure a broad range of psychological well-being constructs and represent a holistic view of positive functioning, and b) to predict important health outcomes that are useful for researchers and clinicians. Both measures had excellent psychometric properties and exhibited convergent validity with exisiting measures of psychological well-being, and both contributed over and above existing measures in predicting a variety of health outcomes.