A 67-year-old man with hormone-refractory (stage D2) prostate cancer was admitted to the hospital because of general malaise and bone pain. The patient had been receiving hormonal therapy, which was discontinued after admission. Instead, 10 mg per day of prednisolone was administered orally. His symptoms improved, and the serum prostate specific antigen (PSA) level decreased markedly. After 18 weeks of treatment with prednisolone, the serum PSA level rose again, and bone pain worsened. The patient died of cancer one month later.