The authors treated a girl with severe aplastic anemia that developed following urinary tract infection. She was referred to our hospital for bone marrow transplantation. The detailed medical history of the patient revealed iatrogenic metamizole sodium overdose that was given during her infection. She responded to a 3-day, high-dose methylprednisolone therapy and consequent conventional dose steroid. The authors observed at first partial and subsequently complete remission of all the hematologic parameters of the patient within 30 days and 4 months, respectively. This case suggests that the history of drug use should be questioned carefully in the patients with aplastic features. Steroid treatment may be an appropiate alternative therapy for aplastic anemia if associated drug use is detected in the medical history.