Autism is a developmental disorder, in which the major characteristics are difficulties in social interaction and communication, and restricted and repetitive behavior. The signs of this disease are often noticed by the age of three by the parents. The signs of autism develop gradually. However, in some cases, regression in the social and communication skills is experienced by autistic children after reaching developmental milestones at a normal pace. There are several risk factors associated with autism which can be classified into genetic and environmental factors. Infections, autoimmune diseases, certain toxins such as alcohol, valproic acid, lead and cocaine and fetal growth restriction are some risk factors during pregnancy. There has been rapid progress in the diagnosis and treatment of autism spectrum disorders. This book will provide interesting topics for research which interested readers can take up. It is a resource guide for experts as well as students.