Asperger's Syndrome, edited by Ami Klin and colleagues of the Yale University Child Study Center, contains contributions from 27 authors representing 13 universities, and several agencies and clinical practices in the United Kingdom, Canada, and the USA. This is a thorough and sorely needed review of the research, diagnostic process, treatment options, and outcomes associated with Asperger's syndrome (AS). Written for professionals, the volume is research-based, and in this relatively new field of study, is as useful in elucidating the questions still requiring investigation as in describing what is currently known. Several aspects of diagnosis are covered, including the development of AS as a formal diagnostic category, a review of clinical features and associated conditions, differential diagnostic considerations (particularly high functioning Autism, Schizoid Personality Disorder, developmental language disorders, and Nonverbal Learning Disability), and special consideration of the contributions of motor functioning, social language use, and neuropsychological functioning to differential diagnosis. Of special interest to neuropsychologists may be the chapter reviewing neuropsychological and neuroimaging studies of AS, from which inferences can be drawn about potential neurodevelopmental processes leading to the manifestations of this disorder. Other chapters focus on genetic factors, clinical outcomes in adolescence and adulthood, pharmacological intervention, and general treatment considerations. A chapter on assessment suggests practical guidelines for assessment of cognitive, neuropsychological, communicative, social–emotional, and adaptive functioning. A set of essays by parents closes the volume, providing an important reconnection to the everyday challenges faced by individuals with AS and their families.