Schwannomas are usually benign tumors that arise from the nerve supporting the Schwann cell. The majority arise at the cranial nerves or nerves of the upper extremities. Most patients with retroperitoneal schwannomas present with vague abdominal or back pain. We present a case in which a retroperitoneal mass thought to be arising from the adrenal gland on computed tomography and magnetic resonance imaging was found after excision to be a Schwannoma. The available literature on retroperitoneal schwannomas is then discussed.