Prospective follow-up study of 70 males with Asperger syndrome (AS), and 70 males with autism more than 5 years after original diagnosis. Instruments used at follow-up included overall clinical assessment, the Diagnostic Interview for Social and Communication Disorders, Wechsler Intelligence Scales, Vineland Adaptive Behavior Scales, and Global Assessment of Functioning Scale. Specific outcome criteria were used. Outcome in AS was good in 27% of cases. However, 26% had a very restricted life, with no occupation/activity and no friends. Outcome in the autism group was significantly worse. Males with AS had worse outcomes than expected given normal to high IQ. However, outcome was considerably better than for the comparison group of individuals with autism.