Squamous cell carcinoma of prostate. A primary squamous cell carcinoma occurring in the prostate of a sixty-nine-year-old man is described. A radical excision that included cystoprostatectomy, total penectomy, scrotectomy, pubic symphysiectomy, and abdominoperineal resection of rectum was done. The patient died of systemic metastases six months after diagnosis. Review of the literature suggests that such a cancer of the prostate is rare, highly aggressive, and responds poorly to any mode of therapy. Histogenesis of this tumor remains controversial; however, it probably does not originate from the prostatic acinar cells. 