Effusions arising from acute pancreatitis are usually small, left sided and self limiting. The incidence of pleural effusions in acute pancreatitis is reported between 3% and 17%. In chronic pancreatitis, as a consequence of fistula and pancreatitic pseudocyst formation or by spontaneous rupture of a pancreatic psudocyst directly into thoracic cavity, extremely large effusions may be seen. When the underlying pacreatic disease is asymptomatic, the diagnosis is made by measuring the amylase content of the pleural fluid. We experience a case of left sided pleural effusions caused by pancreatico-pleural fistula associated with pancreatic pseudocyst. The diagnosis was made by measuring of pleural fluid amylase level(80000U/L). Abdominal CT scan revealed pancreatic pseudocyct and pancreatitis with extension to left pleural space through esophageal hiatus and extension to left subdiaphragmatic space. Left pleural effusions were decreased after fasting, total parenteral nutrition and percutaneous pleural fluid catheter drainage. We reported a case of pleural effusions and pacreatico-pleural fistula asssociated with asymptomatic pancreatic disease with review of literatures.