A newborn with a prenatal diagnosis of left congenital diaphragmatic hernia (CDH) and tetralogy of Fallot with mild pulmonary stenosis underwent CDH repair on day 2 of life. Postoperatively, the infant was extubated to room air with oxygen saturations in the 90s. A routine echocardiogram demonstrated severely decreased left ventricular function and raised concern for an abnormal coronary artery origin, thus prompting cardiac catheterization, which revealed an anomalous single coronary artery from the pulmonary artery. The infant underwent coronary artery reimplantation. Recognition of coronary artery anomalies in a timely manner is imperative for safe repair.