A 29-year-old man who had a history of hospitalization due to alcoholic acute pancreatitis in another hospital. The patient complained of fatigue, and pleural effusion was observed. He was hospitalized with a diagnosis of reactive pleural effusion associated with recurrent pancreatitis. He then started a conservative treatment. Following pleural effusion puncture, he was diagnosed with pancreaticopleural fistula with a pancreatic fistula that reached the thoracic cavity, rather than reactive pleural effusion associated with pancreatitis. An ENPD tube was inserted after pancreatic duct drainage. In addition, thoracic drainage was performed for the pleural effusion. Because the drainage was favorable, the ENPD tube was replaced with a pancreatic duct stent. The thoracic drain was removed after the disappearance of pleural effusion, and the patient was then discharged.