Profound impairment in social interaction is a hallmark of autism spectrum disorders (ASD). Although improvement in social functioning is widely considered to be a crucial target for intervention, social skills treatments for school-age children have been the subject of few controlled investigations. Cognitive behavioral therapy (CBT) social skills groups are commonly used with high functioning children with ASDs; however, the efficacy and durability of these treatments are unknown. Toward this effort, the proposed study is a randomized controlled investigation designed to evaluate short-term effects and maintenance of skills taught in CBT-based social skills groups, at both the behavioral and neural levels. High-functioning children with ASD (8-11 years old) will be randomly assigned to a 12-week cognitive behavioral social skills group or a social play comparison group to control for non-specific therapeutic effects. Functional magnetic resonance imaging (MRI) scans as well as behavioral assessments of social cognition, adaptive functioning, and symptom severity will be acquired at baseline, immediately following treatment, and at a 3-month follow-up. This study should provide much needed information about the short-term efficacy and durability of a CBT approach to social skills treatment, as well as the neural events that accompany and/or predict response to treatment.