We report the case of a 68-year-old man with progressive heart failure due to effusive-constrictive pericarditis. During approximately 1 month, echocardiography revealed rapid progression from pericarditis with effusion without tamponade to pericardial thickening and diastolic dysfunction. Cardiac catheterization revealed that the pressure in the right heart chambers remained high after pericardiocentesis. The patient was rescued by aggressive pericardiectomy and sharp dissection of the epicardium into small fragments. This on-pump beating-heart surgery is known as the waffle procedure.