A 52-year-old female was incidentally found to have a right retroperitoneal mass on follow-up imaging after choledochal cyst surgery. The cyst was diagnosed on intraoperative cholangiogram performed during laparoscopic cholecystectomy for biliary colic. She had no other significant comorbidities. Computed tomography and magnetic resonance imaging following the choledochal cyst surgery showed a 28 mm soft tissue mass of uncertain diagnosis located adjacent to the right kidney and posterior to the inferior vena cava, with differential diagnoses including retroperitoneal lymphadenopathy or an adrenal mass. On serial imaging over 2 years, the mass increased in size from 29 x 20 mm to 27 x 35 mm. Given the enlarging size and diagnostic uncertainty, a retroperitoneoscopic resection of the mass was performed. Intraoperatively, the lesion was distinct to the right adrenal gland and appeared cystic in nature. The mass was successfully removed; the patient recovered without complication and was discharged two days later. Histopathology revealed a 30 x 25 x 7mm cyst lined by pseudostratified ciliated columnar epithelium, with fascicles of smooth muscle in the cyst wall associated with scattered seromucinous glands. Cartilage was not seen; no malignant cells were identified. This appearance was consistent with a retroperitoneal bronchogenic cyst (RBC). Bronchogenic cysts are rare clinical entities caused by abnormal budding of the tracheobronchial tree during embryogenesis. This foregut anomaly is usually found in the mediastinum or thorax. RBC are extremely uncommon and usually located near the left adrenal gland. The above case represents a rare occurrence of a RBC located adjacent to the right kidney.