Understanding how to interact with others is a challenge for people with autism. Impaired social cognition (i.e. perceiving the emotions and intentions of others) makes it difficult to establish friendships and form positive social relationships, and is particularly incapacitating for adolescents with autism who must navigate the world unaided by parents. Advances in our understanding of the social cognitive impairments in autism, provides a grounding for the development of interventions to target this central deficit of autism. The goal of this study is to investigate a group-based cognitive behavioral intervention to improve social-cognitive functioning in adolescents with high-functioning autism (HFA). The study sets out to modify a previously validated form of group-based intervention, Social Cognition and Interaction Training (SCIT), and to optimize its use for adolescents with high functioning autism (HFA). The first step will be to develop a treatment manual to implement this training program, followed by a small, randomized controlled trial to compare the SCIT-A programme with ‘treatment as usual'. Participants will be assessed at baseline, post-treatment (18 weeks later), and at 3-month follow-up and a variety of outcomes and measures, including social cognition, social functioning, and adaptive skills will be assessed. What this means for people with autism: The innovative treatment program will target the specific social cognitive impairments that cause difficulties with social cognition and interactions and is anticipated to help the individuals who take part in this study. The development of a manual is intended to allow for the treatment program to be standardized and, if the current small clinical trial is favorable, for the program to be transferred to a larger study group.