Professional development has been identified as an essential mechanism for enhancing teacher content knowledge and improving instructional practice. In recent years, professional development has been tied to professional development plans of teachers, district goals (Ward, 1999), statewide report card goals (Rink & Williams, 2003), and federally funded grants such as the Carol M. White grant program. Despite this emphasis, professional development programs have been reported in the research as failing to achieve change in teacher practices and in students’ learning (Armour & Yelling, 2004). Teachers themselves report that professional development workshops are the least effective approach to changing teacher practices and improving student achievement (Henry & Opfer, 2004). There is little known about how teachers interpret and use knowledge presented in professional development workshops in their teaching. The purpose of this study was to investigate how teachers generalize their learning from a curriculum model taught in a professional development workshop to their instruction practices. One elementary and three secondary physical education teachers participated in the study. The teachers attended a one-day professional development workshop on the Sport Education curriculum model (Siedentop, 1994), then planned and taught a sport education unit. Teachers were asked to provide a copy of their lesson plans for documentary analysis. Each lesson taught by the teachers was videotaped. Both the lesson plans and the videotaped lessons were analyzed by comparing them to a checklist of Sport Education features taught in the Sport Education workshop. Post-unit interviews were conducted with the teachers to determine their rationales for the inclusion or exclusion of specific features of the model. Analysis of the lesson plans and the videotaped lessons revealed that teachers demonstrated varying degrees of alignment with the Sport Education features presented in the workshop. Post-unit interviews showed that this lack of alignment was as a result of a lack of understanding of the curriculum components and a lack of confidence in making significant instructional change. In conclusion, the one-day professional development workshop was insufficient for teachers to understand the core components of the Sport Education curriculum. Moreover, it seems that teacher’s differential implementation of new pedagogical knowledge may be constrained by their perceptions of classroom context such as expectations for student performance at different grade levels, their competence in managing the class management and their beliefs of how much responsibility students can and should be given in the lessons.Keyword(s): professional development