3 cases of prostatic leiomyosarcoma, observed over a 15-year period, are reported. 2 patients underwent radical surgical treatment only and succumbed to metastatic diffusion after 13 and 29 months, respectively. After palliative surgery, a 3rd man received subsequent radiation therapy for pelvic and pulmonary recurrences, and is alive with tumor after 6 years and 8 months. The diagnostic and therapeutic aspects of this uncommon and aggressive prostatic neoplasm are discussed.