Presenter: Gabriela Arredondo MD | Escuela de Medicina, Tecnológico de Monterrey, México Background: Laparoscopic treatment of liver cyst was first reported in 1991, nowadays can be considered the standard of care. In many cases they are found incidentally on imaging performed for other reasons. Their management varies depending on the diagnosis, risks and symptoms caused. Methods: We present a case of a 52 years old woman, in a check-up ultrasound revealed a 5 x 5.8 cm liver cyst, in 2011; the patient was asymptomatic, so a conservative management was preferred. 8 years later she presented with right back pain, a CT scan showed a enlargement of 13 x 11. 5 x 9.7 cm liver cyst; which was punctured obtaining 750 ml of serous liquid. 2 months later a new CT scan was made revealing the same giant cyst. A laparoscopic unroofing cyst was scheduled, on the operating table, the surgeon was placed between the legs, a 10-mm trocar for laparoscope was inserted above the umbilicus, another 10 mm-trocar was placed 5 cm above the first one, a 5- mm in right flank for lifting up the liver and other 5-mm trocar port for work; Enseal G2 curved (Johnson & Johnson) was used, during surgery a large cyst was observed, it occupied segments VI, VII and VIII of Coinaud; intraoperative ultrasound was used at start of surgery for adequate location and to observe relationship with structures; once the cyst was completely unroofed the laparoscopic ultrasound was used to verify adequate drainage and for excluding another possible cyst. Patient was discharged on day 2. Results: Simple cysts are the most common nonparasitic cystic lesions of the liver and are estimated to occur in approximately 5–18% of the population, with a slight female predominance. They occur as a simple fluid-filled structure, has thin walls, and it is lined by cuboidal epithelium, and up to two septa. Treatment is limited to highly symptomatic patients or those in whom complications occur. Symptoms usually arise as a result of a mass effect, as cyst increase in size, they may become symptomatic. Complication of liver cyst include: intracystic hemorrhage, rupture, torsion, infection, biliary obstruction or compression of adjacent structures and are more likely in larger cysts. Treatment includes nonsurgical procedures such as percutaneous aspiration (with a 100% likely of recurrence), with or without alcohol injection; and surgery: partial excision, complete excision, marsupialization, or liver resection. Conclusion: Laparoscopic unroofing of the cyst wall is particularly indicated in cases of large solitary cysts, or a limited number of cysts located in the anterolateral segments of the liver, sometimes cysts located in the antero and posterosuperior segments of the right liver are frequently assumed to be beyond laparoscopic access. This video shows the feasibility of laparoscopic unroofing liver cyst even in posterosuperior segments.