The hypothesis was tested that weak theory of mind (ToM) and/or emotion recognition (ER) abilities are specific to subjects with autism. Differences in ToM and ER performance were examined between autistic (n = 20), pervasive developmental disorder-not otherwise specified (PDD-NOS) (n = 20), psychiatric control (n = 20), and normal children (n = 20). The clinical groups were matched person-to-person on age and verbal IQ. We used tasks for the matching and the context recognition of emotional expressions, and a set of first- and second-order ToM tasks. Autistic and PDD-NOS children could not be significantly differentiated from each other, nor could they be differentiated from the psychiatric controls with a diagnosis of ADHD (n = 9). The psychiatric controls with conduct disorder or dysthymia performed about as well as normal children. The variance in second-order ToM performance contributed most to differences between diagnostic groups.