In recent years, advances in the rational design of radiopharmaceuticals have helped in the introduction of clinically useful therapeutic agents into the clinic. In particular radiolabeled monoclonal antibodies such as (90)Y-ibritumomab and (131)I-tositumomab have shown to be clinically successful. More recently, (177)Lu has emerged as an attractive radionuclide for use in systemic radiotherapy. Like 131I, it has a longer half-live than (90)Y which is more suitable to the pharmacokinetics of monoclonal antibodies, but its chemistry is similar to (90)Y and, when internalized, it is retained by the tumor whereas 131I can be quickly released. Metastatic prostate cancer is an attractive target for radioimmunotherapy since the cornerstone of current therapy is hormonal therapy, which is only palliative. Prostate cancer is also known to metastasize to areas such as the lymph nodes and bone marrow, sites that are readily accessible to circulating monoclonal antibodies. This review will look at recent advances to the treatment of metastatic prostate cancer with radiolabeled antibodies with a specific emphasis on (177)Lu-huJ591, a labeled monoclonal antibody currently under clinical evaluation.