Teicoplanin is reported to be as effective as vancomycin but with minimal side effects. We report a case of teicoplanin-induced pancytopenia, which has not been demonstrated previously. A 44-year-old man with tetraplegia was treated with a diagnosis of urinary tract infection and pneumonia, and a high-dose of teicoplanin (400 mg every 12 hours) was administered for 4 days inadvertently. Although the infection rapidly improved, the patient developed pancytopenia by the fourth day of teicoplanin therapy, which was improved after reducing the dose of teicoplanin (200 mg/d). Our patient represents a probable case of teicoplanin-induced pancytopenia with adverse drug reaction probability score of 6.