Youth with CHD are at greater risk for neurodevelopmental disorders compared to healthy controls. The aetiology is multi-factorial but includes medical and demographic factors. We sought to characterise the prevalence of neurodevelopmental disorders in patients with CHD. Our population included 206 patients with CHD, aged 3–21, who were referred for neuropsychological evaluation. Neurodevelopmental diagnoses were determined by a licensed psychologist. Rates of neurodevelopmental diagnoses were compared to national prevalence rates. Exploratory analyses (chi-square) examined which medical factors (i.e., cardiac diagnosis, genetic condition, prematurity, seizures, and stroke) were associated with neurodevelopmental diagnosis. There was higher prevalence of neurodevelopmental disorders in CHD when compared to the general population (44%). Rates of attention-deficit/hyperactivity disorder (27.3%), autism spectrum disorder (9.6%), and intellectual disability (5.9%) were notably higher than those seen in the general population (p < .01). Children with a history of aortic obstruction were more likely to be diagnosed with autism (p < .05), and children with genetic conditions were more likely to be diagnosed with an intellectual disability (p < .05). Neurodevelopmental diagnoses were not significantly associated with any other specific medical variables (e.g., cardiac diagnosis, seizures, stroke, prematurity, and antenatal diagnosis). School-aged children were more likely to be diagnosed with any neurodevelopmental disorder and attention-deficit/hyperactivity disorder (31.7%; p < .01) than preschool-age children. In summary, our results confirm that children and adolescents with CHD are at high risk for neurodevelopmental disorders and require ongoing monitoring, care, and support. Children with genetic disorders and those with aortic obstruction may be more at risk for certain neurodevelopmental disorders.