We hereby present a case of a 70-year-old patient who developed constrictive pericarditis after off-pump coronary artery bypass grafting. The diagnosis was based on the fact that, 3 months after the operation, during the follow up appointment, the man complained about dyspnea and the chest pain. The echocardiography as well as the CT scan of the thorax revealed fluid in pericardium and both pleural cavities, which was evacuated via the thoracentesis. Two more recurrent cases of catheterizations, performed in the short period of time, drew our attention to perform the MRI of the heart. Visible thickening of the pericardial wall confirmed the hypothesis. The patient was diagnosed with constructive pericarditis.