Rationale: Thrombotic thrombocytopenic purpura (TTP) is a critical thrombotic microangiopathy involving multiple organs. To the best of our knowledge, there are no reports of TTP complicated by acute aortic dissection. Patient concerns: We herein described a 53-year-old male with TTP who did not have a significant medical history. After immediate plasma exchange and glucocorticoid therapy, the patient's clinical condition improved. However, the patient suddenly experienced chest pain with elevated blood pressure. Diagnoses: Computed tomography angiography suggested acute type B aortic dissection. Interventions: The patient was immediately transferred to the cardiac aortic surgery department for thoracic aortic endovascular repair. Outcomes: The patient was discharged after successful thoracic aortic endovascular repair. Unfortunately, 3 months later, the patient experienced chest and back pain at home and died suddenly, possibly due to the recurrence of aortic dissection. Lessons: Even if patients have no identifiable risk factors, physicians should be aware of this rare and life-threatening acute complication of TTP, which may have multiple causes, including preexisting connective tissue disease, abnormal blood pressure fluctuations, and increased risk of hemorrhage. Early identification and timely treatment of acute aortic dissection are critical for improving prognosis.