Type B aortic dissection (TBAD) is a rare but catastrophic complication of endovascular aneurysm repair (EVAR). We report two cases of TBAD occurring in the perioperative period of EVAR. The intraoperative and postoperative courses were unremarkable. Routine postoperative computed tomography angiography (CTA) revealed TBAD. Conservative treatment was successful, and no adverse aortic events occurred. TBAD that occurs in the perioperative period is likely to be iatrogenic in origin, uncomplicated, and managed with medical therapy: its prognosis is better than when the condition develops in the midterm postoperative period.