Pediatric congenital heart disease comprises a wide spectrum of structural defects. These lesions present in a limited number of ways. An infant presenting with profound shock, cyanosis, or evidence of congestive heart failure should raise the suspicion of congenital heart disease. Although most congenital lesions are diagnosed in utero, the emergency physician must be aware of these cardinal presentations because many patients present in the postnatal period around the time that the ductus arteriosus closes. Aggressive management of cardiopulmonary instability combined with empiric use of prostaglandin E₁ and early pediatric cardiology consultation is essential for positive outcomes.