To determine the risk factors for adverse neurodevelopmental outcomes in school-age children after full flow open-heart surgery for congenital heart disease. The outcome was assessed in 117 children without a genetic comorbidity at a mean age of 10.4 ± 2.5 years. Intelligence was assessed using the Raven's Progressive Matrices and neuromotor function using the Zurich Neuromotor Assessment. Risk factors were retrieved from detailed chart review. The mean intelligence score was 89 ± 16, significantly lower than the norm (P < .001). Cerebral palsy was diagnosed in 10% of patients. Poor neuromotor performance (less than p10) was present in 15% to 20% of the children, depending on the motor task (all P < .001). Pure motor and static balance performance was also significantly impaired when patients with cerebral palsy were excluded (P < .01). Intelligence was only related to socioeconomic status (P = .006), and neuromotor outcome was related to the length of hospital stay and postoperative neurologic abnormalities (P < .03). The extracorporeal circulation time was related to adaptive fine motor performance (P = .05). All other variables were not related to outcome. Children without a genetic comorbidity are at risk of long-term intellectual and motor impairments also after full-flow cardiac repair. Surgery-related parameters play a less important role for adverse outcomes than postoperative complications. Our findings stress the importance of specialized follow-up assessments for all children with CHD undergoing open heart surgery.