Objective exercise testing in patients with repaired tetralogy of Fallot frequently identifies gross deficiencies in exercise capacity. These findings are typically attributed to right ventricular dysfunction, pulmonary valve regurgitation, and pulmonary artery stenosis and are used to justify referrals for surgical or transcatheter interventions. However, the relation between right-sided cardiac abnormalities and exercise capacity in this patient group is poorly understood. Cardiac magnetic resonance imaging correlates of exercise capacity in 37 patients with repaired TOF were retrospectively examined. In conclusion, on multivariate analysis, right ventricular ejection fraction was the only cardiac magnetic resonance imaging predictor of percentage of predicted peak oxygen consumption, oxygen consumption at ventilatory anaerobic threshold, and oxygen pulse.