Performance of a group of 35 youth and adults with High-Functioning Autism (HFA) was compared with a typical developing (TD) group on three Advanced Theory of Mind tests. The distinction between the social-cognitive and social-perceptual components of Theory of Mind was also explored. The HFA group had more difficulties in all tasks. Performance on the two social-cognitive tests was highly correlated in the HFA group, but these were not related with the social-perceptual component. These results suggest that the youth with HFA have difficulties on all the components of social knowledge but may be using different underlying cognitive abilities depending on the nature of the task.