Occult cardiac injury following blunt trauma is more common than generally suspected. Myocardial contusion is not rare, however, it is generally a benign disorder which often remains undiagnosed. We report a case of a right atrial rupture after blunt chest trauma causing a tamponade. A 24-year-old man was involved in a violent car accident and he presented in a state of collapse. A multislice computed tomography indicated a pericardial effusion (Figure 1). A transthoracic echocardiography was performed and confirmed pericardial effusion which was hyperechoic (Figure 2, Movie 1). Concerns about a possible mass in the right atrium led to examination with transesophageal echocardiography (Figure 3, Movie 2) which revealed the presence of a voluminous mass in the right atrium. The patient successfully underwent cardiac surgery to remove the mass, identified as a blood clot, and to repair the atrial tear. The present case is of special interest because of the rarity of documented incidents of blunt chest trauma causing right atrial tear and illustrates the usefulness of transesophageal echocardiography in completing the diagnosis in the event of haemopericardium.