We report a case of a 40-year-old man with cystosarcoma phyllodes of the prostate. This tumour is very rare in the prostate. The stroma of the tumour was cellular and composed of elongated cells with spindle shaped nuclei, scanty, pale and eosinophilic cytoplasm. Some cells showed nuclear atypia but the cells did not display mitotic activity. We categorised this tumour as benign. The suprapubic prostatectomy was done. The patient is alive and well after three years.