Many instances of coronary artery anomalies are documented in the literature; however, the detection and treatment of an asymmetric, large aortic cusp causing obstruction of a coronary ostium in a symptomatic infant remains unreported. We present a case of a two-month-old infant with an enlarged right coronary cusp obstructing the left coronary ostium, requiring emergent repair by relocating the left coronary button and reconstructing the sinus of Valsalva with autologous pericardium. This procedure preserved native aortic valve function, and the child remains asymptomatic months after discharge.