There is increasing public and healthcare provider awareness about the early signs and developmental challenges of children with autistic spectrum disorders (ASDs). Healthcare professionals are guided by several major policy statements regarding the diagnosis and management of autism. There remain substantial gaps between these guidelines and families' needs during the diagnostic process. This article provides a developmental and behavioral perspective for the professionals who desire to find guideposts in task of supporting families throughout the diagnostic process of autism. We illustrate the diversity of the ASDs using the International Classification of Functioning, Disability and Health Model and describe developmental and behavioral perspectives about the autism diagnostic process. Our overall goal is to enhance parent and professional collaboration in promoting the establishment of medical homes, accessing the highest quality developmental assessments, and implementing comprehensive supports for parents of children with ASDs.