In recent years, the neuropeptide oxytocin (OT) has been implicated in a wide range of social behaviors including attachment bonds, emotion recognition, eye gaze to social cues, and memory for social information. Social impairments represent one of the most intractable features of autism, and evidence now suggests that OT biology is dysregulated in individuals with this disorder. The central aim of this study is to test whether OT administration to children with autism increases their quality and quantity of social interactions and enhances their ability to process emotional and social information. Findings from initial single-dose OT administration studies in teenaged and adult males with autism have shown improvement in some aspects of social functioning, but replication and extension to well-controlled treatment trials with younger male and female participants is necessary to evaluate effectiveness. Therefore, this study investigates the effect of intranasal OT on social cognition and behavior immediately following a single-dose (24IU) and following a 4-week period of OT (24IU BID) administration in a sample of 50 participants with autism aged 6 to 12 years. The primary outcome for this study is change in social behavior, as determined by parent ratings on the Social Responsiveness Scale (SRS) after the 4-week treatment period. Secondary outcomes are changes in functioning on laboratory-based measures of social behavior and cognition (i.e., child facial emotion recognition; eye gaze to emotional faces; and, contagious laughing and yawning) following single-dose and 4-week OT administration. Research in a small study sample (N=13) also identified treatment responders and non-responders to a single-dose of OT. Thus, this investigation identifies biological and social variables (i.e., pretreatment plasma OT levels, SRS scores, and laboratory social measures) that may influence treatment response efficacy in the larger study sample. This research offers a unique opportunity to translate established basic scientific training in social neurobiology to clinical research in autism. Conducting this project and receiving co-mentoring by a basic scientist and an autism clinician will provide the fellow with expertise in examining the biological, behavioral, cognitive, and clinical features of autism with the potential to lead to novel therapeutic approaches for autism.