Objective: This study aimed at comparing different levels of Theory of Mind (ToM) in children with autism, intellectual disability, attention deficit- hyperactivity disorder (ADHD) and normal children.

Methods & Materials: A causal-comparative study was conducted. Seventy-nine (36 females, 43 males) 7-11 year-old students were selected through simple and cluster random sampling. The numbers of students suffering from various disorders were as follows: autism (8 females, 12 males), intellectual disability (10 females, 10 males), ADHD (9 females, 13 males), and normal ones (10 females, 10 males). For data collection Morris et al’s (1999) Theory of Mind (ToM) test was used. Data were analyzed with multivariate analysis of variance.

Results: Results showed that children with autism scored the lowest in the overall test and in the subscales of ToM children with intellectual disability scored lower than children with ADHD, and normal children scored the highest. There were statistically significant differences between the four groups (p<0.001). However, there was no significant difference in the levels of ToM between the two genders.

Conclusion: Children with autism, intellectual disability and ADHD have numerous problems in ToM abilities which probably negatively affect their social performance.