In this study, it was aimed to examine the effect of a peer education program developed on the acquisitions of knowledge and skill of writing and implementing social stories by students attending primary school, and the effect of social stories delivered by peers who have completed the program (peer tutor) on the acquisition of crossing skills by students with developmental disabilities (peer tutees), maintenance of this skill two weeks after the end of the implementation, and generalization with a different street. In the study, social validity data were collected from peer tutees and peer tutors using a subjective evaluation approach. The study was carried out with a total of six participants consisting of three students aged between 7 and 9 years who attend a primary school in a province in East Anatolian Region, two of whom are diagnosed with autism spectrum disorder and one of whom is diagnosed with a mild intellectual disability, and these students' peers with normal development. Peer tutees were taught how to write and deliver social stories with one-on-one instruction by following the steps of Powerpoint presentation, modeling, experimenting, and providing feedback. In the study, a multiple probe design with probe conditions across dyads (peer tutor - peer tutees), one of the single subject research models, was used to evaluate the effect of social stories written and delivered by peer tutors on peer tutees' learning crossing skills. Research results showed that peer tutors acquired the social story writing and implementation skill accurately by 100%. After the instruction delivered by the peers who acquired the social story writing and implementation skill, it was observed that peer tutees acquired the crossing skill and could generalize it to a different street, and that two peer tutees with the ASD continued to exhibit this skill they acquired accurately by 100% two weeks after the end of the study. Maintenance data were not collected from the third peer tutee due to the closure of schools. Social validity data collected from peer tutees and peer tutors using a subjective evaluation approach showed that both peer tutees and peer tutors had positive opinions on the target skill, social stories, and research results. These results were discussed within the context of the literature, and suggestions were made to include peer mediated implementations in teaching different skills with different methods and to make the use of social stories in teaching safety skills by parents, siblings, specialists working in the field and teachers widespread.