Autism Spectrum Disorder (ASD) is a developmental disorder characterized by abnormalities in speech and communication, impaired social functioning and repetitive behaviors and restricted interests. Oxytocin (OT) is peptide that is known for its peripheral effects on facilitating uterine contractions and milk let-down; however, studies, mainly with rodents and non-human primates, has found that OT is involved in affiliative behaviors, including sexual behavior, mother-infant and adult-adult pair-bond formation, separation distress, and other aspects of social attachment. Moreover, OT is known to play an important role in repetitive behaviors and stress reactivity. Given that repetitive behaviors and deficits in social interaction are core symptom domains of autism, and that OT is involved in the regulation of repetitive and affiliative behaviors, it is believed that OT may play a role in the etiology of autism. Moreover, preliminary data obtained by Hollander and colleagues suggests that OT may be of value in treating core autism symptoms. Specifically, synthetic oxytocin administered via intravenous infusion to adults with autism spectrum disorders (ASD) produced significant reductions in repetitive behaviors and facilitated social cognition/memory in a double-blind, placebo-controlled cross-over laboratory challenge. Encouraged by these findings, the primary aim of this study is to investigate the safety and therapeutic efficacy of intranasal OT in treating repetitive behaviors and social functioning/cognitive deficits in adults with ASD. This research embraces a translational approach to develop a novel treatment for core ASD symptoms; given that there are currently no Food and Drug Administration (FDA) approved medication treatments for core ASD symptoms, this research addresses an important unmet need in the field. The goal of this study is to evaluate the safety and efficacy of repeated Intranasal Oxytocin Treatment (INOT)administration in adults with ASD.