Researchers at Stanford University are currently recruiting children with autism and their parents to participate in a study examining the effectiveness of a center-based Pivotal Response Treatment (PRT) program in targeting social communication abilities in young children with autism. We are currently recruiting children diagnosed with ASD and social communication deficits, aged 2:0 to 3:11 years. Children who are eligible based on behavioral screening assessments will be randomly assigned to either an immediate treatment (PRT) group or a delayed treatment group (DTG). If randomized into the PRT group, the 12-week treatment will consist of a combination of one weekly 60-minute individual parent training session and 12 weekly hours (approximately 3 hours per day for 4 days per week) with your child in a center-based group preschool environment at Stanford University. If randomized into the delayed treatment group, the children will wait 12 weeks to receive the PRT treatment and continue any treatment they are receiving as usual in the community.