Pneumopericardium is the presence of air in the pericardial space. In adults, it may be seen in the context with severe blunt chest trauma, pneumothorax, pneumoperitoneum, or other causes of pneumomediastinum. The diagnosis is made by computed tomography scan of the thorax and abdomen that allows the additional detection of concomitant injuries. Possible causes of the pneumopericardium such as tracheobronchial or oesophageal tears have to be excluded by bronchoscopy or esophagogastroduodenoscopy. Usually, pneumopericardium is self-limiting requiring no specific therapy. However, a continuous monitoring of the electrocardiography and the blood pressure is necessary at an intermediate care unit. Tension pneumopericardium causing a life-threatening cardiac tamponade requires an immediate pericardial aspiration, the subsequent pericardial drainage via a pericardial window or emergent open subxyphoid approach to the pericardium.