Primary small cell carcinoma of the prostate (SCCP) is rare. Natural history of this tumor is similar to that of bronchogenic small cell carcinoma. A majority of patients with SCCP have distant metastasis at presentation. Because the disease is rapidly fatal, the incidence of brain metastasis from SCCP is not known. A case of primary SCCP with multiple subcutaneous and lymph node metastases is presented. The patient failed to respond to systemic hormone therapy but had a near complete response to multiple agent chemotherapy consisting of cyclophosphamide, adriamycin, and vincristine. Multiple brain metastases subsequently developed, and he responded poorly to cranial irradiation. The clinical behavior of this cancer being similar to that of bronchogenic small cell carcinoma, it supports the recommendation of computerized axial tomography of the brain to be included in the staging workup of patients with SCCP. Prophylactic cranial irradiation might be of value in patients with a complete response to chemotherapy.