The current paper provides an overview of an evidence-based treatment, Pivotal Response Treatment (PRT), for autism spectrum disorder (ASD). The paper describes PRT principles and then illustrates the approach using two case reports. The children are preschool-aged children with high-functioning ASD. They were participating in a four-month clinical trial of PRT. At the start of treatment, they presented with significant social communication impairments, including a minimal understanding of reciprocity, limited play skills, and repetitive behaviors and speech. The paper outlines how behavioral treatment goals were identified and then how activities were designed, using principles of PRT, to target skill acquisition. Following the treatment course, both children made substantial and meaningful gains in social communication skill development.