There is a growing need to consider the cultural responsiveness of behavioral interventions for individuals with disabilities, given increasing diversity in the United States. This study examined the effectiveness of peer-mediated pivotal response treatment (PRT) on social behaviors of Korean American children with autism, an understudied yet growing part of the group of Asians who have been overrepresented in autism diagnoses. In addition, this study investigated the social validity of the intervention, using a post-treatment questionnaire and family interviews to gather stakeholders' perceptions. A multiple baseline design across four dyads was used. Results indicated that peer-mediated PRT effectively increased social interactions between focus children and their peers. Stakeholders reported positive social validity for the intervention. Recommendations and implications for future researchers and practitioners are presented.