Autism spectrum disorder is a heritable, developmental disability that is characterized by challenges with social communication and the presence of restrictive and/or repetitive patterns of behavior. Autism spectrum disorder affects development and quality of life from very early development through old age. Social workers play a number of different roles in supporting and advocating for individuals on the autism spectrum and their families. It is important that social workers understand the etiology, diagnosis and treatment of autism spectrum disorder, how it manifests throughout the lifespan, and challenges faced by families affected by ASD.