Aneurysmal fibrous histiocytoma (AFH) is a variant of dermatofibroma that grows rapidly and is associated with bleeding. We report a case of AFH associated with severe anemia. A 34-year-old woman with a bleeding tumor on the right lateral thigh underwent resection of the tumor involving the deep fascia, followed by blood transfusion. The defect was subsequently repaired uneventfully using skin grafting. The patient showed no recurrence. We diagnosed the patient with AFH based on postoperative histopathological evaluation findings. AFH is often indistinguishable from other diseases and is therefore diagnostically challenging. Local recurrence may occur despite the benign nature of the tumor; therefore, careful postoperative follow-up is important.