Adequate exposure of the mitral valve is essential to the safe and effective performance of valve replacement. We describe a successful mitral valve replacement performed in a patient who had undergone a right pneumonectomy. After a median sternotomy was made, the mitral valve was approached through an incision in the left atrial appendage that extended to the origin of the left superior pulmonary vein. The operation was uncomplicated, and the patient made an uneventful recovery.