A 49-year-old man was admitted for evaluation of a left pleural effusion. Thoracenthesis yielded a hemorrhagic pleural effusion with a high percentage of eosinophils (15.9%). Although there were no significant abdominal signs, serological examinations demonstrated a marked increase of pancreatic enzyme activity. Moreover, abdominal CT demonstrated cystic changes between the tail of the pancreas and the spleen. Accordingly ERP was performed under pressure, and contrast medium draining from the pancreas was observed. Pancreatic pleural effusion in this patient consisted of pancreatic juice retained in the thoracic cavity, which resulted from intrapancreatic fistulation connecting to the thoracic cavity due to a pancreatic cyst caused by chronic pancreatitis. The present report indicates that we should investigate the retention of eosinophilic pleural effusion considering not only the possibility of thoracic disease, but also the possibility of a pleural effusion derived from abdominal diseases.