The social behavior of children and adolescents with Autism Spectrum Disorder was evaluated weekly over 19 weeks of a social skills training program. Participants' vocalizations were coded as initiating, responding, or other (e.g., self-talk). Participants' interactions were coded as dyadic peer interactions, dyadic leader interactions, interactions with a group of peers, interactions with a group of peer(s) and leader(s), or time spent by self. Over the course of the intervention, participants made fewer initiating and other vocalizations, more responding vocalizations, spent more time interacting with a group of peers, and spent marginally less time interacting with a leader. Gender, age, and intervention attendance effects on social behavior are also noted.