We describe the combined use of inhaled nitric oxide and heliox (79% helium and 21% oxygen) as a rescue therapy for a critically ill infant with localized interstitial pulmonary emphysema and pulmonary hypertension. Conventional interventions were ineffective, not feasible, or unlikely to take effect in time, during this infant's acute critical illness. We added heliox based on its known pulmonary effects, and inhaled nitric oxide to improve oxygenation, after echocardiographic evidence of high right-ventricular pressure. The infant made a full recovery. To our knowledge this is the first case report of heliox and inhaled nitric oxide used simultaneously in localized interstitial pulmonary emphysema.