Coronary artery dissection due to blunt chest trauma (traumatic coronary artery dissection [TCAD]) may heal spontaneously, and some surgeons believe that conservative or elective treat-ments are sufficient, provided that there are no progressing ischemic symptoms. However, we report a patient who experienced sudden ventricular fibrillation (VF) during initial medical care for trauma injuries. The 32-year-old woman was riding in a passenger car when an accident occurred, and was subsequently transported to our emergency department. Twelve-lead electrocardiography revealed ST segment elevation in leads II, III, and aVF, although her vital signs remained stable. Therefore, we prioritized assessing the trauma at other sites, and VF suddenly occurred. Coronary angiography was performed with repeated defibrillation and chest compressions, which resulted in recovery of spontaneous circulation. Occlusion was observed in the right coronary artery, which we treated with balloon angioplasty. However, intravascular ultrasonography (IVUS) subsequently revealed coronary artery dissection, a stent was placed, and the patient successfully recovered. Therefore, IVUS may be useful for diagnosing TCAD, and swift intervention is needed if TCAD is detected.