In this article, the authors assert that professional development (PD) projects have an orientation that guides the design and implementation of the entire project; a construct that the authors term “PD Project Orientation”. The aim of this study was to validate the existence of this new construct. Using various data sources from nine PD projects, the authors generated and characterized five PD project orientations. This study has implications for those designing and implementing PD for science teachers, as well as PD evaluators.