Pericardial diseases manifest as a part of a systemic condition or in isolation. The clinical presentation is driven by inflammation (i.e. pericarditis), excess fluid accumulation (pericardial effusion), or pericardial stiffening (constriction). Corresponding symptoms and signs may include pain, stigmata of systemic inflammation, atrial arrhythmia, haemodynamic compromise, or chronic heart failure. Pericardial tumours and space-occupying lesions are uncommon and may be incidentally detected or present as one of the above-mentioned forms of pericardial disease. Aetiological work-up is usually unnecessary in acute pericarditis but is indicated in the incessant/chronic form and to exclude bacterial infection. Pericardial effusions need to be investigated when large and promptly evacuated when associated with haemodynamic compromise. The hallmark of constrictive physiology is ventricular interdependence. It is important to distinguish transient constriction and to treat inflammation according to aetiology prior to making a decision on surgical relief by pericardiectomy.