Asperger's disorder is a pervasive developmental disorder that shares similar features of social impairment disorder, restricted interests, and repetitive behaviors with autistic disorder. Although both Asperger's disorder and autistic disorder persist into adulthood, autistic disorder is usually apparent before the age of 3, while Asperger's disorder usually manifests itself at preschool age. Asperger's disorder in the majority of cases is not associated with delay in language development and there is an increased likelihood to seek social interactions and to engage in activities and friendship with others. In contrast to autistic disorder, most Asperger's disorder patients have normal intellectual functioning and some have motor clumsiness. Although the etiology of Asperger's disorder is still undetermined, this article will review the assessment and treatment interventions that could improve the prognosis of this illness. The historical background, epidemiology, diagnostic features, differential diagnosis, and course and overall management/treatment of Asperger's disorder will be discussed. Despite the absence of a cure for Asperger's disorder, the awareness of its distinctive clinical features that differentiate it from autistic disorder could improve its prognosis and differentiate response to treatment and comorbid conditions.