We report the case of an infant born prematurely at 27 weeks gestational age with life-threatening pulmonary hypertension crisis as a result of left upper pulmonary vein stenosis. Surgical treatment consisted of a lobectomy, which is a safe and effective procedure. Evidence strongly suggests that the venous stenosis may have resulted from hypertonic drugs infused through an umbilical catheter facing the upper left venous-atrial junction.