Asperger’s syndrome (AS) is a pervasive developmental disorder characterized by a so-called triad of impairments, including significant impairment with reciprocal social interaction (extreme egocentricity), social communication, and different dimensions of imagination such as restricted range of interests, preoccupations, and perspective-taking difficulties. AS falls within the autism spectrum of conditions (ASC) along with autism and high-functioning autism (HFA). Although the term disorder has been used in the academic literature for many years, there is a growing preference for using the descriptor autism “conditions” because this acknowledges positive as well as negative characteristics. Although several formal diagnostic criteria for AS have been put forward, many are considered limited in clinical practice because they exclude key features such as motor clumsiness and unusual language usage rather than highlighting no delay in development. Within the DSM-5 (2013), AS has been removed as a separate diagnostic description, with AS, autism, and atypical autism being classified under the broader category of autism spectrum disorder. Although AS is recognized as a separate diagnosis within the ICD-10, its position within the proposed ICD-11 remains unclear. There is also recognition that many diagnostic criteria do not reflect the quality of social impairments, idiosyncratic interests, communication styles, and age of emergence of first features typical of AS.