A rare case of histopathologically revealed renal tuberculosis caused by intravesical bacillus Calmette-Guerin (BCG) therapy is reported. A 67-year-old man was admitted complaining of fever and micturition pain. He had been undergoing prophylactic BCG instillation therapy for recurrent superficial bladder tumor. Physical examination was unremarkable. The tuberculin skin test was negative. Mycobacterium tuberculosis (MT) was not demonstrated by acid-fast staining and culture of urine. However, MT was isolated by the polymerase chain reaction method. In the following 7 days, symptoms were dissolved with administration of isoniazid, rifampicin and piperacillin. Two months later, nephroureterectomy was performed because of left renal pelvic tumor. Tuberculomas were also found in the renal parenchyma which showed no MT by Ziehl-Neelsen's method. Anti-tuberculous medication was not given postoperatively. Two months after operation, he is free of disease with normal urine examination and positive tuberculin skin test measuring 12 x 10 mm.