Combination of The Childhood Autism Rating Scale™ Second Edition - Standard Clinical Tool (CARS2-ST) with criteria for autism spectrum disorder (ASD) based on Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) is thought to improve diagnostic process. To meet diagnostic needs, localized, Indonesian-translated version of CARS2-ST is developed. Therefore, assessment of construct validity of the Indonesian-language translated CARS2-ST must be performed. A cross-sectional study was conducted in Child Development Center in Surabaya, Indonesia from August to December 2019. Diagnosis of ASD then performed by using CARS2-ST and DSM-5 criteria. To assess construct validity, principal components analysis and Kaiser-varimax rotation was performed for CARS2-ST in order to determine factors. DSM-5 criteria for ASD was used to compare scale.There were 201 children aged 2 - 6 years old with reported speech and behavior problems. Sixty-six children were diagnosed for ASD. Factor analysis using Kaiser-varimax rotation indicates a significant two factors: social communication and interaction factor and restrictive stereotyped behaviors and sensory factor sensitivites. The factors satisfyingly reflects the criteria for ASD in DSM-5.Construct validity of Indonesian-translated version of CARS2-ST is confirmed, as shown by its correspondence with DSM-5 criteria for diagnosing . This study supports the continued relevance of the Indonesian CARS2-ST in ASD assessment.