We report a case of esophagopericardial fistula with subsequent purulent pericarditis that was diagnosed with computed tomography and echocardiography. In a patient with non-specific chest pain and vague past history, serial echocardiography demonstrated rapid aggravation of pyopneumopericardium and chest CT scan showed a foreign body that caused the fistula in the esophageal wall. Removal of a piece of fish bone, closure of the fistula, and creation of a pericardial window for continuous drainage were performed through a low lateral thoracotomy.