A 56 year-old man complaining of dry cough, dyspnea, chest pain, fever, and chills was admitted to the emergency room. The patient had a history of esophagectomy and esophagogastrostomy and subsequent radiotherapy because of an esophageal cancer. After the emergency echocardiography revealed a small amount of pericardial effusion and pneumopericardium. Upper GI contrast study showed a fistulous tract between the stomach and the pericardium, and an emergency operation was done under the diagnosis of gastropericardial fistula. The patient expired postoperative seven days later. Gastropericardial fistula caused by a peptic ulcer perforation after the esophagectomy and esophagogastrostomy operation is a very rare complication and brings forth a disastrous result. Early detection using the chest radiography, electrocardiogram, upper Gl study, echocardiography and a review of physical examination, and an immediate treatment are therefore mandatory.