Background/Aim: Prostate cancer frequently causes bone metastases and skeletal events that impair quality of life (QoL) and survival. The alpha emitter radium-223 is a new drug that improves treatment in men with castration-resistant prostate cancer (CRPC) and bone metastases. Our aim was to evaluate the effectiveness of radium-223. Subjects and Methods: In this retrospective study we enrolled 48 subjects. Pain reduction, alkaline phosphatase (ALP), time to first symptomatic skeletal event, and QoL were the variables we evaluated. Results: Radium-223 was well tolerated, with a manageable toxicity profile and a modest objective response rate. A considerable difference in serum ALP levels before and after treatment was observed, with a significant correlation between pain relief and QoL, which showed a value of R2 to 0.44 with a slope of 1.50 (p = 0.0021). Conclusions: Radium-223 showed a clinical benefit, with a reduction in pain symptoms in 58% of patients. Radium-223 was shown to be an effective and well-tolerated therapeutic option in patients with metastatic CRPC progressing after docetaxel plus prednisone treatment.