Background: Executive function is very important in the children's overall development. The goal of this study was to assess the executive function in children with intellectual disability (ID) through the use of the Behavior Rating Inventory of Executive Function (BRIEF) teacher version. An additional goal was to examine the differences in executive function in relation to child's sex, level and aetiology of ID. Method: The sample consisted of 90 children with ID attending two special education schools in Sarajevo, Bosnia and Herzegovina. There were 42 children with mild ID and 48 children with moderate ID. Of those, 54 were boys and 36 were girls. Children were classified into three etiological categories: 30 children with Down syndrome, 30 children with other genetic cause or organic brain injury and 30 children with unknown aetiology of ID. Special education teachers, who knew the children for at least 6 months filled the BRIEF. Results: Children with ID had a significant deficit in executive function as measured by the BRIEF. There were no statistically significant differences in executive function in relation to the child's sex. Level of ID had a significant effect on executive function. In relation to the aetiology of ID, the only significant difference was on the Shift scale of the BRIEF. Conclusions: Knowing what executive function is most impaired in children with ID will help professionals design better intervention strategies. More attention needs to be given to the assessment of executive function and its subsequent intervention in the school settings.