Bone is the most common site of metastasis in metastatic castration-resistant prostate cancer (mCRPC), which is associated with pain and skeletal events. Radium-223 dichloride (Xofigo) is an alphaemitting radioactive isotope that can specifically target bone lesions. Herein, we report the results of a retrospective analysis that documents our experience in the use of radium-223. Data from 63 patients (pts) with mCRPC who underwent radium-223 treatment from December 2015 to September 2017 were collected. Radium-223 (55 kBq/kg) was administered every 4 weeks for up to 6 cycles. The primary endpoint was OS. Radium-223 was administered as first line therapy in 11 pts, as second line in 19 pts, as third line in 16 pts and in successive lines in 17 pts; 42 pts out of 63 (67%) completed all six cycles. Within one month after the end of 6 cycles of radium-223, 15 pts out of 42 (35.7%) had achieved PR, 11 pts out of 42 (26.2%) had SD and 14 pts out of 42 (33.3%) had PD. Levels of pain decreased with progressive cycles of radium-223. After a minimum follow-up of 2 months and a maximum of 43 months, median OS was 15 months and median PFS was 8 months. The most frequent radium-223 related toxicity was low grade haematologic toxicity, predominantly G1-G2, that occurred halfway through treatment in about 75% of pts. The favourable results reported herein confirm that radium-223 can be considered well tolerated and effective in mCRPC, and is associated with significant decreases in pain. Prostate cancer is one of the most commonly diagnosed malignancies and a leading cause of cancer death in men 1. In 2012, there were over 1,000,000 newly diagnosed cases and >307,000 deaths from the disease worldwide 1. In Europe, in 2018, there were an estimated 450,000 new cases of prostate cancer 2 , and in the US, prostate cancer is the second leading cause of cancer deaths following those of the lung and bronchus 3. Even if several treatments are local, including radical prostatectomy, external radiotherapy and brachytherapy, which may allow eradication of disease in some patients (pts), roughly one-third of men will develop distant metastases 4. Even if long-term survival is relatively high, averaging 10 years in those with localised disease, in men with metastatic disease the 5-year survival rate decreases dramatically to approximately 30% 5. Such poor survival rates can be attributed in large part to resistance to treatment in which aggressive variants of prostate cancer arise following the accumulation of mutations in key tumour suppressor genes 6,7. Moreover, androgen depletion is known to induce genes involved in cancer progression and metastasis and the epithelial-to mesenchymal transition, which have implicated the bone-epithelial interaction as a key player in the progression of prostate cancer 8. Bone metastases dominate the clinical picture of advanced prostate cancer and are a major source of morbidity in metastatic disease 9. In pts with recurrence, bone is, in fact, the most common site of metastasis affecting more than 90% o...