Autism is a pervasive neurodevelopment disorder, primarily encompassing difficulties in the social, language, and communicative domains. One of the most common social cognitive theories of autism is based on theory of mind (ToM), the "mentalizing" ability needed to infer that others have their own beliefs and desires in order to understand their behavior. In the current study, this hypothesis was tested using Wellman and Liu's scaled ToM tasks. These were employed in the assessment of ToM development of verbal, school-aged high-functioning boys with autism spectrum disorder (ASD). The results indicated that children with ASD performed significantly worse than normal children on ToM tasks (Z = 4.7; P < 0 .001). However, it was shown that some of the ASD children were able to pass desire and false-belief tasks whereas none of them could succeed in knowledge and real-apparent emotion tasks.