This study disentangled the influences of language and social processing on communication in autism spectrum disorder (ASD) by examining whether gesture and speech production differs as a function of social context. The results indicate that, unlike other adolescents, adolescents with ASD did not increase their coherency and engagement in the presence of a visible listener, and that greater coherency and engagement were related to lesser social and communicative impairments. Additionally, the results indicated that adolescents with ASD produced sparser speech and fewer gestures conveying supplementary information, and that both of these effects increased in the presence of a visible listener. Together, these findings suggest that interpersonal communication deficits in ASD are driven more strongly by social processing than language processing.