This article focuses on the possibilities of teaching in a play-based curriculum, which has become an issue of international relevance. As a domain of study, the Developmental Education approach was taken in the early grades of Dutch primary schools (grades 1-4, ages 4-8). The article describes the theoretical basis of the approach and how it is elaborated in a play-based curriculum for early years classrooms. Particularly the teachers' strategies for the promotion of development will be discussed in more detail. Finally, the article presents a piece of the evidence base of this approach by reporting a research on vocabulary acquisition. Despite methodological limitations of the empirical study, the evidence suggests that teaching in a play-based curriculum is not only theoretically plausible and practically feasible, but also seems to be effectively useful for the attainment of positive outcomes (on vocabulary learning) as compared to a strictly teacher-driven approach. © 2013 Copyright Taylor and Francis Group, LLC.