Asperger syndrome (AS) is a neurodevelopmental disorder defined under the umbrella of pervasive developmental disorders (PDDs) in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The diagnosis was subsumed by the autism spectrum disorder (ASD) diagnosis when the DSM-5 was published in 2013, but the term is still used by many clinicians. At its core, the syndrome involves the key features of ASD–social impairments paired with a restricted range of interests and/or repetitive behaviors—while also involving no speech or cognitive delays. AS has [Page 91]often been regarded as a milder form of autism. This entry describes the syndrome, its diagnostic complexities, and general intervention strategies.