This study examined critical features of secondary special educator's experiences with transition professional development to predict variables most likely to influence performance of transition planning and services. Results included the extent to which secondary special educators are prepared to perform transition practices, the relationship between preparation and the frequency of performance, and specific variables predictive of higher levels of implementation. The results confirm that training matters if special educators are to implement transition interventions and services. Professionals with formal transition coursework and high rates of professional development were more likely to implement transition practices. Implications are offered for establishing specialized professional development originating from established course content sustained and supported with ongoing professional development. (Contains 3 tables.)