BACKGROUNDS/AIMS: Simple liver cysts were easily recognizable with the advanced imaging procedures, such as ultrasound and computed tomography scan. A large cyst or significant symptoms were indications for the treatments. Ablation therapy with sclerotic agents was effective, but there were several complications including severe pain. With the surgical cyst unroofing method introduced, we compared the cyst unroofing method and ablation therapy. METHODS: Between March 1997 and May 2011, we performed treatments of simple liver cysts in 27 patients. There were 23 women and 4 men (age range: 42-84 years; mean age: 64 years). The cyst unroofing was undergone with laparoscopic (n=13) and open technique (n=1). The ablation therapy was performed with ethanol (n=13) and acetic acid (n=1). RESULTS: The usual symptoms of the liver cysts were abdominal mass (n=7), indigestion (n=4), abdominal discomfort (n=3), and the increasing size of the cysts (n=4). The mean diameter of the cysts was 10.9 cm. The cyst unroofing method was performed effectively in 14 patients. One patient had bleeding during operation, and was converted to the open technique. One patient had a bile leak from the cyst, but it was successfully closed with the laparoscopic technique. Among the 14 cases with the ablation therapy, there were 4 complications: hematoma (n=1); cyst leaking during aspiration (n=2); acute renal failure (n=1); and death due to acetic acid intoxication (n=1). CONCLUSIONS: Laparoscopic cyst unroofing was more effective and safer in management than the ablation therapy in simple liver cysts.