Introduction and objective: Early diagnosis of developmental disorders in children can help initiate interventions to support development and improve mental health and well-being for both parents and children. Autism spectrum disorder is among the developmental disorders with the latest diagnosis. Screening procedures using validated tools may be important for early identification of autism spectrum disorder. The purpose of the present study was to verify the psychometric properties of the Polish version of one such tool, the Autism Spectrum Quotient: Children’s Version. Materials and methods: The study included 192 children aged 4 to 11 years diagnosed with autism spectrum disorder (all had a formal psychiatric diagnosis of childhood autism, Asperger syndrome, or atypical autism based on ICD-10 criteria), with normal intellectual functioning, and 520 typically developing children of the same age range. Results: The reliability and validity of the Polish version of the Autism Spectrum Quotient: Children’s Version are adequate. A cut-off score of ≥67 showed high sensitivity and specificity, and was optimal for distinguishing between the study groups. Conclusions: The Autism Spectrum Quotient: Children’s Version in Polish version makes it possible to detect symptoms of autism spectrum disorder in clinical samples, and may be a useful tool for researching autistic traits in the general population.