Chest pain after thoracic trauma may be a symptom of cardiac injury or myocardial infarction. A 63-year-old healthy man had chest pain after blunt chest trauma in a motor vehicle accident. Chest computed tomography scan showed a displaced sternal fracture, lung contusion in the left upper lobe, atelectasis and consolidation in both lower lobes, and bilateral haemothorax. Electrocardiography showed ST elevation (2 mm) in leads II, III, and aVF and ST depression (2 mm) in leads I and aVL, consistent with acute inferior myocardial infarction. Urgent coronary angiography showed ostial occlusion of the right coronary artery. After the right coronary occlusion was passed with a guide wire, dissection of the right coronary artery was observed and treated with a balloon and stent to reestablish normal flow. This case emphasizes the importance of a high index of suspicion for coronary artery injury and myocardial infarction after blunt chest trauma.