The purpose of this study was to investigate the effect of therapeutic horseback riding on social skills of children with autism spectrum disorder. Participants were 6 children with autism spectrum disorder in a special education center for autistic children in Shiraz, Iran. The hypothesis of the study was that participants would demonstrate significant improvement in social skills following a 4-week horseback riding intervention. Using a One Group Pre and Post Test design, the Stone's social skills Scale was administered to assess the social skills of children with autism spectrum disorder as pretest. Then the subjects participated in a 4-week therapeutic horseback riding program consisting of two 45 minute session of riding per week. After completion of the 4-week intervention the post-test was administered. Paired-samples "t-test" was utilized to analyze the data. The results indicated that therapeutic horseback riding improves affective understanding and perspective taking, initiating interactions and maintaining interactions significantly. It can be concluded that therapeutic horseback riding has a positive effect on social skills improvement.