INTRODUCTION:While the overall prevalence of autism is 1.7% in the United States of America, research has demonstrated a two- to five-fold increase in CHD. The Cardiac Neurodevelopmental Outcome Collaborative recommends screening for autism from infancy through adolescence. This study investigated the frequency of autism concerns at a single Cardiac Neurodevelopmental Program and examined current clinical practice as a way to improve quality of care. MATERIALS AND METHODS:Patients (n = 134; mean age = 9.0 years) included children with high-risk CHD who completed a neurodevelopmental evaluation following a formalised referral to the Cardiac Neurodevelopmental Program between 2018 and 2019. Retrospective chart review included parent report on the Behaviour Assessment System for Children-3 and Adaptive Behaviour Assessment System-3. Descriptive and correlation analyses were completed. RESULTS:In this sample, 11.2% presented with autism-related concerns at referral, 2 were diagnosed with autism, 9 were referred to an autism specialist (6 confirmed diagnosis; 3 not completed). Thus, at least 5.9% of the sample were diagnosed with autism following thorough clinical evaluation. Analyses showed atypicality, along with deficient adaptability, leisure, social, and communication skills. Frequency of early intervention, school supports, and relation with comorbidities are reported. DISCUSSION:Prior to assessment recommendations by the Cardiac Neurodevelopmental Outcome Collaborative, autism screening may not be completed systematically in clinical care for CHD. The current sample demonstrates a high frequency of autism in the typically referred clinical sample. Commonly used parent-report measures may reveal concerns but will not help diagnosis. Systematic use of an autism screener is essential.