The purpose of the current study was to evaluate the effectiveness of combining milieu therapy and functional communication training (FCT)] to replace aberrant behavior with functional communicative skills in 3 male preschool or elementary aged children with Autism Spectrum Disorders (ASD). Study activities were conducted in the natural environments of the participants and parents acted as change agents. A concurrent multiple baseline design across participants was used to evaluate the effectiveness of the modified milieu therapy intervention. Results indicate that aberrant behavior decreased concurrent with an increase in total percentage of communication responses (PCR). The children maintained communication and low rates of aberrant behavior, and generalized their communication from the home to the classroom. A discussion of limitations and future research directions is included.