This videotape depicts the workup and two operative procedures of an eight-month-old female with a hypoplastic right lung. Specifically, the videotape includes the history, standard x-rays, a cardiac catheterization, a VQ scan, and an echocardiogram. Operative footage of a right pneumonectomy performed for the hypoplastic right lung is included. Postoperatively, the patient developed an overshifting of the mediastinum to the right with respiratory distress. Serial x-rays demonstrating this overshift are shown. A new technique of correcting the mediastinal overshift by performing a right thoracotomy and inserting an inflatable silastic tissue expander with a subcutaneous injection port is shown. This technique was devised to allow for future expansion of the device as the child grows.