Autism spectrum disorder consists of a group of developmental disabilities which present social and behavioral challenges. The different disorders which are a part of this group of disorders are Asperger’s syndrome, pervasive developmental disorder not otherwise specified (PDD-NOS), and autistic disorder. The diagnosis of these disorders cannot be done through medical tests. Instead, it relies on observation of the behavior and development of a child. The therapies to manage autism spectrum disorders focus on providing intervention as early as possible to maximize their effectiveness. They generally help the children learn basic skills such as walking, talking and interacting with other people. This book includes some of the vital pieces of work being conducted across the world, on the diagnosis and therapies for autism spectrum disorders. It will also provide interesting topics for research which interested readers can take up. Students, researchers, experts and all associated with the research on these disorders will benefit alike from this book.