Acute pericarditis is an inflammation of the pericardium. Different etiologies are known, and can be classified in three groups: infectious, neoplastic and auto-immun. The diagnosis is based essentially on clinical signs and should be raised by position and respiratory dependent chest pain, especially when it follows a viral infection, and a pericardial friction rub on cardiac auscultation. An ECG and an echocardiography should be performed to assess the presence of a pericardial effusion. A diffuse and concave ST elevation permits the distinction with myocardial ischemia. The first line therapy is an association between NSAR and colchicine, the latter has shown to reduce the risk of recurrence.