Small cell anaplastic carcinoma of the prostate (SCCP) is a rare entity; a literature review disclosed fewer than 150 cases. SCCP has an aggressive course, and both local and distant failure is common. The optimal treatment method has not been clearly established. We review our experience with 7 patients, with attention paid to clinical and pathological details based on a review of the histological specimens. Three patients had mixed tumors of both SCCP and adenocarcinoma, 3 had pure adenocarcinomas that recurred as small cell, and 1 had pure small cell. Our series confirms the aggressive nature of the disease, with all patients dying of their disease < or = 42 months after diagnosis. All patients progressed locally, and at least 5 later developed distant metastases. Treatment with combination chemotherapy and/or hormones resulted in short-lived responses in most patients. We recommend use of hormonal manipulation and combination chemotherapy as well as surgery and/or radiation therapy to the prostate for local control and emphasize that histologic recognition of the entity is important for proper treatment.