Just as individual teachers have orientations to teaching and learning science that influence their practice, we assert that professional development (PD) projects also have an orientation that guides the design and implementation of the entire project; a construct we term "PD Project Orientation". The purpose of this study was to validate the existence of this new construct. Using various data sources from nine PD projects we generated and characterized five PD project orientations. We illustrate the characteristics of each orientation with descriptions from specific projects and show the frequency of the orientations and how these orientations were emphasized within each PD project. This study has implications for those designing and implementing PD for science teachers, as well as PD evaluators.