Our theoretical framework is based on Vygotsky's Zone of Proximal Development focusing on adults' involvement in children's play and we argue that teachers' involvement is crucial in supporting children's play skills. Particularly, this study examines early childhood teachers' (ECTs) sociodramatic and imaginative play skills and their development through a drama professional development program (DPDP). A 13-week DPDP on ECTs' socio-dramatic and imaginative play skills was designed and implemented. Thirteen in-service ECTs attended, four of whom provided the data for this paper. Data collection for this study includedpractice video recordings and their analysis with the use of an observational tool by the researchers and the participants. The results revealed three socio-dramatic and imaginative play skills that ECTs must have: Role Enactment, Interactive Dialogue and Interactive Dialogue with Role Enactment. These skills and their characteristics, support literature on effective teachers' involvement, ECTs' general teaching skills and the principles of improvisation. We propose the ECTs' Zone of Proximal Action is an adult-led zone, which exemplifies teachers' potential action in supporting children's play.