Mediastinal lipomatosis is a rare benign condition characterized by a large amount of mature adipose tissue in the mediastinum. We present the case of an 86-year-old male who was admitted to the hospital for analysis of his progressive dyspnea. After careful examination, the patient was diagnosed with severe aortic valve stenosis and extensive mediastinal lipomatosis. This rare coincidence of aortic valve disease and mediastinal lipoma was treated by aortic valve replacement and an extensive debulking procedure.