Approximately 3,000 patients will be enrolled in this registry. Patients eligible for enrollment will be men aged at least 18 years, with a confirmed diagnosis of adenocarcinoma of the prostate, with documented metastatic prostate cancer and documented castration resistance. Patients will be enrolled at the time of initiating a new systemic anticancer mCRPC treatment or during surveillance; for the purpose of the registry, at enrollment, initiation of a new systemic mCRPC treatment is considered as ±30 days from a patient's baseline data collection.