A 72-year-old male was admitted to our hospital due to high fever and dyspnea. Echocardiography and bacterial culture of pericardial fluid revealed purulent pericarditis caused by Streptococcus. Despite pericardial drainage and antibiotic therapy, hemodynamic instability due to constriction persisted. At 12th hospital day, partial pericardiectomy with left thoracotomy was performed. After the operation, his hemodynamics improved gradually, and was discharged from the hospital on the 54th post operative day without recurrence of infection nor constriction.