Malignant tumours arising from the basal cells of the prostate gland are extremely rare, and the majority of reports in the literature suggest a relatively indolent clinical course. We report a case of infiltrative basaloid carcinoma of the prostate in a 68-year old man that did not respond to systemic chemotherapy. It is essential that this aggressive disease is differentiated from more indolent basaloid proliferations, as metastatic spread can occur and outcome may be poor.