The social vulnerabilities associated with young children with autism are recognized as important intervention targets due to their influence on subsequent development. Current research suggests that interventions that combine motivational and social components can create meaningful changes in social functioning. Simultaneously, it is hypothesized that parent delivery of such strategies can invoke increases in these core social behaviors and parent engagement. This study examined the effects of teaching parents to implement a social engagement intervention with their children. The results indicated that the use of this parent-delivered social intervention led to (a) increases in their children's use of eye contact, directed positive affect, and verbal initiations, (b) increases in parent positive affect and synchronous engagement, and (c) generalized increases in parent and child behaviors. (Contains 2 tables and 7 figures.)