Introduction: Social stories (SS) are among evidence-based practices that are known to be effective in support of behavioral and educational needs of children with autism spectrum disorder (ASD). It is very important for teachers to present evidence-based practices with high application reliability for children with ASD to reach their target skills. This study aimed to examine the effect of SS that were designed and presented by pre-service teachers (PST) on target social skill (sharing toys, saying hello, and forming a line) acquisition, maintenance, and generalization of preschool children with ASD.