Children with autism often display differences in functional and symbolic play and may experience barriers to social inclusion with peers in preschool settings. Therefore, interventions supporting social play between children with autism and their peers that can be feasibly implemented by teachers in inclusive settings are needed. A teacher-implemented peer-mediated Stay Play Talk (SPT; Goldstein et al. in Top Lang Disord 27(2):182-199, 2007) intervention package targeting the type of play children with autism engage in with peers was implemented using a concurrent multiple baseline design across four participant/peer dyads. Using a cascading coaching model with behavioral skills training, a teacher was trained in intervention strategies and then taught and supported four peers to implement the intervention. In addition to visual analysis, to statistically analyze effects, we calculated effect sizes using the parametric measure standardized mean difference. A functional relation between the intervention and increases in interactive play and initiations and decreases in solitary play was demonstrated across all dyads. Results generalized to novel settings and maintained following withdrawal of teacher support. Results suggest that SPT can be effectively implemented by a teacher to support interactive play between children with and without autism in an inclusive classroom. Implications for future research and clinical practice are discussed.