Purpose: Positive youth development is increasingly recognized as important to the health and well-being of adolescents. We describe the development of a brief, standardized instrument for measuring outcomes and indicators important for youth development evaluation. Additionally, we describe the psychometric properties of these constructs. Methods: A coalition of representatives from 12 community organizations, funders, and researchers identified four core outcomes associated with positive youth development likely able to be affected by community-based youth-serving agencies. Items were piloted and field tested to test feasibility and establish face validity with experts and with adolescents. Furthermore, we tested construct reliability using factor analysis to determine how well the items reflected underlying constructs. Results: Items representing four empirical constructs were used to survey 389 adolescents. Those who participated in the pilot took an average of 11 minutes to complete the survey. Overall, 24 items loaded on to six discrete factors representing the outcomes of basic social skills, caring adult relationships, and decision-making. When participants under age 13 years were eliminated from the analysis, items were more cohesive, resulting in a five-factor solution with all items loading at .40 or higher. Conclusions: The four youth development outcomes identified by community-based youth-serving organizations factor into reliable constructs with acceptable alpha coefficients for adolescents over age 13. A major strength of this youth development outcome measurement is that it has an easy-to-administer formal, which allows community-based programs to receive feedback for program improvement, and to track the effectiveness of their programs for funders. (c) 2006 Society for Adolescent Medicine. All rights reserved.