Emphysema is a common indication for adult pulmonary transplantation. Double-lung transplantation is increasingly the preferred approach because severe posttransplant native lung hyperinflation (NLH) following single-lung transplantation may compromise allograft lung function. We describe successful emergency use of bronchoscopic lung volume reduction using endobronchial valves (EBVs) [Zephyr; Emphasys Medical; Redwood, CA] in a single-lung transplant recipient who was critically ill with ventilator dependence from complications of NLH and at excessive risk for lung volume reduction surgery or pneumonectomy. Following placement of 17 valves in all segments of the native lung, atelectasis of the native lung was accompanied by volume expansion of the allograft. Immediately following valve placement, peak airway pressure decreased and alveolar ventilation increased. The patient was subsequently weaned from mechanical ventilation. This report suggests the need for clinical trials to evaluate the effectiveness of EBVs in single-lung transplant recipients with less critical functional impairment associated with NLH.