ABSTRACT The pericardium is not simply a two‐layered membrane surrounding the heart and great vessels. Pericardial effusion is the most common manifestation of various pathological conditions involving the pericardium. Therefore, we are tempted to think of the pericardium as a virtual space containing only fluid, but it can also contain solid and cystic lesions. We must recall that clinical symptoms are non‐specific and may mimic cardiac, pulmonary, or pleural diseases. Imaging findings are not specific for a particular pathology, but when combined with the clinical history, can provide sufficient information to make an accurate differential diagnosis. In this review, we will identify selected entities affecting the pericardium, from benign to malignant, with a brief description of their clinical characteristics.