Sarcomatoid carcinoma (SC) of prostate gland is a rare biphasic tumour. In about half of cases, initial diagnosis is acinar adenocarcinoma, followed by nonsurgical therapy, with a subsequent diagnosis of SC. The survival rate is lower. We report a case of an 59-years-old man with unusual histopathologic finding of prostate sarcomatoid carcinoma, showing characteristics of ductal prostatic adenocarcinoma and prostatic stromal sarcoma-like appearance. Ductal adenocarcinoma was characterized by tall columnar cells with abundant amphophilic to eosinophil cytoplasm. Pleomorphic sarcoma was characterized to have overall glandular growth pattern, simulating a malignant phyllodes tumour. Estrogen and progesterone receptors showed nuclear immunostaining in mesenchymal multinucleated giant cells. In conclusion, SC of the prostate is an exceedingly rare tumour. Retrospective analyses render prostate SC as one of the most aggressive prostate malignancies. The prognosis is dismal regardless of other histologic or clinical findings.