The aim of the present study was to assess mental flexibility and set maintenance of a group of individuals with Asperger syndrome (AS) or high-functioning autism (HFA) (N = 13; mean age 16,4), as compared with a matched group of typically developing children and adolescents (N = 13; mean age 15,6) on the computerized version of the Wisconsin Card Sorting Test (WCST). The participants in the AS/HFA group performed less well than the controls on all categories of the WCST, but the differences did not reach conventional statistical significance on most categories of the WCST. On the category failure to maintain set, however, the AS/HFA participants performed significantly less well than the controls, suggesting a deficit of focused attention.