The purpose of this study was to identify the underlying structure of the trait domain of Conscientiousness using scales drawn from 7 major personality inventories. Thirty-six scales conceptually related to Conscientiousness were administered to a large community sample (N= 737); analyses of those scales revealed a hierarchical structure with 6 factors: industriousness, order, self-control, responsibility, traditionalism, and virtue. All 6 factors demonstrated excellent convergent validity. Three of the 6 factors, industriousness, order, and self-control, showed good discriminant validity. The remaining 3 factors—responsibility, traditionalism and virtue—appear to be interstitial constructs located equally between Conscientiousness and the remaining Big Five dimensions. In addition, the 6 underlying factors had both differential predictive validity and provided incremental validity beyond the general factor of Conscientiousness when used to predict a variety of criterion variables, including work dedication, drug use, and health behaviors.