Chapter one presents a synopsis of developmental disabilities (DDs); it looks at the history, prevalence, causes, manifestations, treatment options and challenges faced by parents and their children with DDs particularly, autism. Chapter two describes the four categories of DDs, presents the history of autism spectrum disorder (ASD), risk factors, common manifestations and diagnostic criteria for ASD as stipulated by the Diagnostic and Statistical Manual of Mental Health Disorders, Fourth Edition, Revised-Text (DSM-IV-TR) and DSM-V. Chapter three describes the assessment process for diagnosing DDs, the various diagnostic instruments for autism and best diagnostic practices. Chapter four explains the different ways to provide support to children with DDs in order to meet the unique needs of each individual. Chapter five discusses the process for developing and implementing an individual plan to meet the unique educational needs of a child with DDs. particularly, autism. Chapter six presents the cultural and linguistic factors influencing people's views regarding DDs and provides guidelines for working with families of persons with autism and other developmental disabilities.