The purpose of this article is to describe two studies that examined the effects of training and coaching on preservice teachers' implementation of an intervention focused on teaching play to young children with disabilities. A multiple-baseline across teachers single-case research design was used to systematically examine the relation between didactic training alone and didactic training plus coaching on teachers' use of the intervention. The results indicated that didactic training alone was not associated with changes in teacher behaviors. Training plus coaching, however, resulted in teachers' increased use of the intervention package. Child pretend play behaviors also were examined in Study II and increased with the teachers' high-fidelity use of the intervention. Implications for practice and research related to preservice and inservice professional development are discussed.