We report a 67-year-old man with highly symptomatic polycystic liver disease. Fenestration was selected to treat symptoms because the cysts were scattered diffusely and the normal liver volume was limited. Although this patient was relieved from symptoms of liver cysts consequently, several severe postoperative complications including disseminated intravascular coagulation, respiratory failure, liver failure, and biliary leakage occurred resulting in a 6-month postoperative hospital stay. Although various treatments for symptomatic adult polycystic liver disease have been advocated, a definitive treatment remains controversial, especially in diffuse adult polycystic liver disease. Fenestration is one of the alternative treatments for the patients whose cysts are difficult to resect. However high morbidity rate should be carefully assessed, if extensive fenestration is needed to treat diffuse adult polycystic liver disease. Further consideration of appropriate treatments for diffuse adult polycystic liver disease is needed.