Bronchogenic cysts are foregut-derived developmental anomalies most commonly encountered in the mediastinum and rarely in the abdomen or retroperitoneally. A comprehensive review of the English-language literature of subdiaphragmatic bronchogenic cysts (sBCs) revealed only 48 reported cases of sBC. Although most cases are incidentally discovered, preoperative differential diagnosis often includes tumors with malignant potential and necessitates surgical resection to obtain a definitive diagnosis. Herein, we describe a case of a 46-year-old female presenting with intermittent left flank pain, upon which computed tomography demonstrated a retroperitoneal mass. Upon resection, histopathology revealed the mass to be a thin-walled cystic mass lined by ciliated columnar cells and cartilage, consistent with a subdiaphragmatic bronchogenic cyst. A comprehensive literature review of sBC was also performed.