Book excerpt: This handbook details best practices and discusses ongoing challenges in assessment and diagnosis of autism spectrum disorder (ASD). Chapters address assessment and diagnostic protocols, developmental considerations in ASD assessment, and issues concerning comorbid psychological and medical conditions. Various aspects of the disorder are emphasized throughout the handbook - from assessment in adolescent and adult populations to the latest findings in neuropsychology. The book concludes with future directions for research and clinical applications, focusing on universal screening, improved assessment methods, and earlier and more accurate diagnosis. Topics featured in this handbook include: Types of ASD assessment. Report writing for ASD evaluations. Stress and satisfaction in the diagnostic process. Clinical and neuropsychological perspectives from comorbid diagnosis of ASD and ADHD. Executive functions in ASD. The Handbook of Assessment and Diagnosis of Autism Spectrum Disorder is an essential reference for researchers, clinicians, professionals, and graduate students in clinical child and school psychology, child and adolescent psychiatry, and social work as well as rehabilitation medicine/therapy, behavioral therapy, pediatrics, and educational psychology.