Objective: Hereditary hemorrhagic telangiectasia (HHT) may be associated with paradoxical cerebral embolism caused by pulmonary arteriovenous malformation (PAVM). We present a case of HHT diagnosed by progressive anemia during anticoagulant therapy following mechanical thrombectomy. Case Presentation:The patient was a 59-year-old woman who presented with acute stroke due to intracranial large vessel occlusion. Mechanical thrombectomy was successfully performed and the thrombus was retrieved. Postoperatively, anticoagulant therapy was started; however, she developed progressive anemia, which was associated with marked weakness, although no bleeding source was detected. Thorough postoperative imaging studies revealed PAVMs, which may be a source of cerebral embolism. It was noted that she frequently had episodes of epistaxis and a family history of PAVM. Embolization of PAVMs was performed to prevent the recurrence of embolic disorders. After this procedure, anticoagulant therapy was safely discontinued, which resulted in the improvement of anemia. Conclusion:Physicians need to consider the possibility of HHT associated with PAVM which can cause paradoxical cerebral embolism.