Background and purpose: Assessment of executive functions in parents and relatives of individuals with autism disorder is one of the best ways to determine the role of different aspects of executive functions in the etiology of autism. Present study aimed to compare executive functions (inhibition & cognitive flexibility) in parents and siblings of autistic and normal children.

Method: Present study was a casual-comparative research. Sample consisted of 248 individuals (124 parents and siblings of autistic individuals and 124 parents and siblings of normal individual). Data were collected using Autism Spectrum Screening Questionnaire (ASSQ), Stroop Test, and Wisconsin Card Sorting Test.

Results: Results showed significant difference between the groups in terms of their performance in both tasks. In other words, parents and siblings of autistic individuals had poorer performance in inhibition and cognitive flexibility (p < .001).

Conclusion: Impairment in executive functions in individuals with autism disorder and their family can help researchers to identify the nature of autism-related executive functions disorders. Implications are discussed further.