An arterial switch is the corrective procedure of choice for d-transposition of the great arteries but may be associated with increased morbidity and mortality when performed in low-birth-weight infants. Conversely, delaying surgery often leads to left ventricular "deconditioning" as pulmonary arteriolar resistance decreases. We present an infant with a birth weight of 940 g with d-transposition of the great arteries with an intact ventricular septum whose bilateral pulmonary artery branch stenosis allowed for maintenance of near systemic left ventricular pressure, thereby protecting against deconditioning. This case also represents the smallest reported patient to undergo a successful balloon atrial septostomy.