Children with developmental disabilities usually experience difficulties in social communication that influence peer interaction and making friendship during their stay in preschool setting. Regardless of the presence of assistant teacher in the kindergarten group, peers rarely spontaneously engage in interaction with children with developmental disabilities. One of numerous interventions for children with developmental disabilities in inclusive settings is peer mediated instruction and intervention (PMII). PMII is primarily designed to improve the social and communicative interactions among young children with developmental disabilities (autism spectrum disorder, deaf- blind, intellectual disabilities, etc.) and their typically developing peers. In this study, children with disabilities were already included in the regular preschool setting so the goal of the study was to raise the quality of their inclusion through PMII. The program focused on two children with developmental disabilities (autism spectrum disorder and childhood apraxia of speech) and 6 previously prepared social competent peers all educated in the kindergarten group of 24 children. Socially competent peers in existing groups were thought ways how to help and reinforce communication skills. The main goal was to implement appropriate mean of communication for child with childhood apraxia of speech and enhance interaction and communication skills of both children with disabilities. The program lasted four months. Results have shown that both children with disabilities have initiated and responded on peer interaction more often and maintained in parallel play with peers longer after implementation of the intervention. Child with childhood apraxia od speech more often used appropriate mean of communication then before intervention. Intervention has motivated not only previously prepared and educated peers, but also other peers in group, respectively, to include target children more often in play and interaction. Advantages, limitations and results of implementation of program PMII in kindergarten group will be demonstrated. Results encourage us to continue exploring new ideas and implement different types of supporting inclusive settings and therapy.