Introduction: Cystic lymphangiomas (CL) are congenital tumours that arise due to abnormal fusion of lymphatic channels during development. They are typically diagnosed in children and are commonly located in the head and neck. Rarely they can occur in adults and can be located intra-abdominally. CL may be asymptomatic; however larger lesions can cause mass effect with compression of surrounding structures, leading to a variety of symptoms and signs depending on size and location of the mass. Because of these factors, CL can be particularly challenging to diagnose and manage, particularly in the adult population. Case presentation: We present a case of a 38-year-old female who presented with increasing right upper quadrant pain with radiation to the back. CT abdomen revealed an ovoid, hypodense non-enhancing structure abutting the IVC and uncinate process of the pancreas, measuring 5.5cm in greatest dimension. The structure caused anterior displacement of the duodenum and renal vein compression. Patient underwent a successful laparoscopic resection of the retroduodenal mass aided by the use of intraoperative ultrasound. Histopathology confirmed diagnosis of CL. Patient had no postoperative complications and had complete resolution of symptoms. Conclusion: We describe a rare case of retroperitoneal cystic lymphangioma successfully managed by laparoscopic resection. Improved awareness of this rare but benign disease entity may facilitate minimally invasive local resection, avoiding the unnecessary morbidity from major oncological resection.