A 66-year-old man was referred to our hospital with a complaint of lumbago. Digital rectal examination showed an enlarged, irregular prostate with stony hardness. The serum level of prostate specific antigen (PSA) was elevated. Abdominal computed tomography showed enlarged common iliac and paraaortic lymph nodes, and multiple liver metastases. Bone scintigraphy showed multiple bone metastases. Histological and immunohistochemical examinations indicated small cell carcinoma and adenocarcinoma of the prostate. Chemotherapy could not be performed due to acute hepatic failure. The patient died 1 month after his first visit.