Strontium-89 is a beta emitting radioisotope, avidly taken up by osteoblastic metastatic prostatic cancer. In both open and controlled studies, it has been shown to palliate metastatic pain effectively. It is as effective as conventional radiotherapy in palliation of the primary site(s) of pain, but in addition, it seems to delay pain progression. Its role is confined to palliation of pain in the absence of actual or impending complications (cord compression or pathological fractures). Bone marrow suppression makes it unsuitable for myelosuppressed patients. Cost is the main limitation to its use. It is a useful alternative to hemibody radiotherapy and to local treatment in selected patients. Its use in other tumour types (especially breast cancer) is currently under investigation. Trials investigating its use to delay onset of pain in symptom free relapsing patients should be considered.