Globally, there are more bilingual speakers than monolingual speakers; however, scant research evidence exists regarding social communication development and outcomes for bilingual children with autism spectrum disorder (ASD). A stronger evidence base will facilitate health professionals and educators providing accurate recommendations regarding language use. This study employed a longitudinal cohort design to compare social and communication skills, at baseline and over 12 months, for 60 monolingual and 60 bilingual children with ASD receiving community based early intervention. We found few differences at intake, and no difference in the magnitude of change over 12 months for this cohort. Findings support the notion that there is no basis on which to discourage home language use with bilingual children with ASD.