We present a case of a 14-year-old boy who presented with symptoms resulting from an anomalous left coronary artery. He underwent corrective surgery to reimplant the left coronary artery into the left coronary sinus. After 3 months, he developed new symptoms. On further investigation, a tight ostial stenosis of the left coronary artery was observed and the patient underwent left internal mammary artery to left anterior descending coronary artery bypass graft. This case showcases the importance of multi-modality imaging in the diagnosis of coronary artery anomalies and potential post-surgical complications.