The application of 70% helium-30% oxygen mixtures by tight-fitting face mask in the emergency management of large airway obstruction is well known. We present the case of an infant with severe large airway obstruction and respiratory failure that was unresponsive to the more traditional approaches of airway management, including the delivery of He-O2 by face mask, endotracheal intubation, and conventional mechanical ventilation with oxygen alone. This case was successfully managed with He-O2, when concentrations of O2 were lower than those previously reported in association with conventional mechanical ventilation, until the obstruction could be surgically corrected. We suggest using a new combination of the low-density helium-oxygen gas mixtures and conventional mechanical ventilation, both of which are readily available in most intensive care units.