As developmental scientists cease to perceive adolescence as a period of inevitable turmoil and adopt the Positive Youth Development (PYD) perspective, psychometrically sound measurement tools will be needed to assess adolescents' positive attributes. In this article we examine the longitudinal stability of the very short version of the PYD scale developed as part of the 4-H Study of PYD. Using a sample of 7,071 adolescents (60% female) followed between Grades 5 and 12, our results suggest general stability of PYD across adolescence, both in terms of mean levels and rank-order stability. We also show that both a global measure of PYD and the individual Five Cs of PYD consistently correlate with important criterion measures (i.e., contribution, depressive symptoms, and problem behaviors) in expected ways. Although our results suggest weak relationships among our three criteria, we especially note that across adolescence PYD becomes more strongly correlated with contribution but less strongly correlated with depressive symptoms, and that confidence becomes more strongly related to depressive symptoms. We discuss implications for use of the present PYD measure in youth development programs.