DiGeorge Syndrome (DGS) is a congenital disorder that affects the thymus, parathyroid glands, and heart and brain. Thymus involvement in DGS may vary between absence/hypoplasia of thymus to various forms of reduced T cell function. TBX1 deficiency causes a number of distinct vascular and heart defects, suggesting multiple roles in cardiovascular development, specifically, formation and growth of the pharyngeal arch arteries, growth and septation of the outflow tract of the heart, interventricular septation, and conal alignment. Here the authors describe a case of DGS presenting with severe combined immunodeficiency, esophageal atresia, and tracheoesophageal fistula (TEF). DGS is an important differential diagnosis in TEF.