Abiraterone is a novel, selective, irreversible, and potent inhibitor of 17-[alpha]-hydroxylase/17,20-lyase (CYP17) enzymatic activity that has recently been demonstrated to further reduce testosterone levels in the blood to undetectable range (< 1 ng/dL) and is suggested to reduce de novo intratumor androgen synthesis. Abiraterone demonstrated activity in castration resistant prostate cancer patients previously treated with docetaxel chemotherapy. Recently, results of a phase III trial comparing abiraterone plus prednisone vs placebo plus prednisone in asymptomatic and without visceral metastasis, castration-resistant metastatic prostate cancer patients, demonstrated a better radiological progression free survival for abiraterone treated patients and a trend towards a better survival was clear for abiraterone treated patients.