Eleven years after the publication of the first guidelines worldwide on pericardial diseases by the European Society of Cardiology (ESC), the international expert group of the ESC has updated the original document of 28 pages with 275 references. The final version of the new guidelines is more voluminous with 44 pages of recommendations but only 233 references. A continuing medical education (CME) certified update of the 2004 guidelines was published in the journal Herz volume 7/2014. In comparison to 2004 the 2015 guidelines have remained virtually unchanged in the sections detailing diagnostics, differential diagnosis, pathology and pathophysiology. Substantial progress has been made in magnetic resonance imaging (MRI) of pericarditis and epicarditis and in the practically universal recommendation of colchicine for all forms of pericarditis and pericardial effusion, whether acute, chronic or recurrent. This can truly be called progress; however, little has changed since 2004 even in tertiary referral centers or universities with respect to the etiological classification of acute or recurrent forms of pericarditis or pericardial effusion. By classifying pericardial syndromes much too often as idiopathic when a malignant or bacterial cause has been excluded, the underlying cause is often overlooked. Standstill in diagnosis is in the end regress because we too often lag behind our actual diagnostic and interventional possibilities.