Coronary artery dissection and aneurysm culminating in acute myocardial infarction are rare after blunt chest trauma. We are reporting a case of a previously healthy 52-year-old man who presented with right inferior lobe contusion, pleural effusion, right interlobar fissure effusion, bone fracture of right fourth rib, and acute inferior wall myocardial infarction and who experienced blunt trauma in his right chest wall by an airbag deployment in a car accident. Coronary angiography showed an aneurysm in the middle of right coronary artery with 70% afferent narrowing just distal to the aneurysm with no visible atherosclerotic lesion. A 4.0×20 mm TEXUS Liberté stent in the lesion was deployed, and a good coronary flow was obtained without residual stenosis and the aneurysm vanished.