Alagille syndrome is a dominantly inherited multisystem disorder involving multiple organs including the liver, heart, eyes, face, and skeleton. Congenital heart defects, the majority of which are right-sided, contribute significantly to the mortality of these patients. We report a patient with Alagille syndrome who presented with mitral valve regurgitation requiring valvuloplasty and subsequent mitral valve replacement. The patient was ultimately diagnosed with anomalous origin of the left coronary artery from the pulmonary artery and underwent successful reimplantation.