This CME review takes stock of the progress in the etiology, pathophysiology, diagnostics and treatment of pericarditis and pericardial effusion brought about by the publication of the 2nd European Society of Cardiology (ESC) guidelines on the management of pericardial diseases in 2015. It also emphasizes special forms, which have received less attention in the past, such as therapy-refractory (incessant), effusive-constrictive and constrictive pericarditis and the treatment of acute and recurrent pericarditis with colchicine. After the diagnosis of pericarditis with or without effusion has been made, the first step is to clarify its etiology, which affects the clinical symptoms, course, treatment and the prognosis. In this aspect the requirements of the guidelines and the reality of an etiological classification of pericardial diseases diverge in many cases. The diagnosis of "idiopathic" acute or recurrent pericarditis is still much too often the result of insufficient efforts to find the cause. Too often only malignant and bacterial forms are excluded. If the etiology is known local intrapericardial treatment with the already inserted pigtail catheter from the diagnostic pericardial puncture can be carried out with few systemic side effects. The 2015 ESC guidelines recommend colchicine as first line treatment in all forms of pericarditis except for neoplastic pericardial effusion. It accelerates healing and reduces the frequency of recurrence of pericarditis but cannot eliminate recurrence completely. The best treatment and prevention of recurrence is the eradication of the underlying etiological cause.