Retroperitoneal fibrosis is a rare condition characterized by the presence of inflammatory and fibrous retroperitoneal tissue that surrounds and often encases abdominal structures. In this report we describe an unusual presentation of retroperitoneal fibrosis and inferior vena cava (IVC) obstruction that was unidentified by noninvasive testing and ultimately diagnosed using exercise right heart catheterization and venography. Exercise hemodynamic catheterization revealed a high pressure gradient across the IVC obstruction during exercise that resulted in reduced preload and inappropriately low cardiac output reserve. The patient ultimately underwent angioplasty and stenting of the obstruction resulting in resolution of his symptoms. © 2013 Wiley Periodicals, Inc.