Asperger's Syndrome (AS) is a developmental disorder characterized by social impairment, highly circumscribed interests, repetitive behaviors, and motor clumsiness. The social impairment features of AS are similar to characteristics of social anxiety disorder (SAD). However, little is known about the comorbidity of these disorders or the treatment of social anxiety in the context of AS. The present single-subject report examines the use of cognitive-behavior therapy (CBT) in treating SAD in an adult with comorbid AS. The results suggest that a 14-week course of CBT was successful in reducing symptoms of anxiety and comorbid depression. In addition, improvements in social skills were observed (e.g., appropriate eye contact, conversational skills). Limitations and future directions for research and treatment are discussed.