The development of agents targeting androgen signalling holds promise for men with castration-resistant prostate cancer (CRPC).The emerging role of abiraterone acetate (AA), a novel, orally administered androgen synthesis inhibitor, is critically analysed.Data were acquired from critically important original research published in peer-reviewed literature or presented at conferences conducted by the American Society of Clinical Oncology and the European Society of Medical Oncology.The major findings are addressed in an evidence-based, objective, and balanced fashion.AA specifically inhibits CYP17 and substantially reduces serum androgen levels without inducing significant adrenal insufficiency. A phase 3 trial reported a significant extension of survival in metastatic CRPC with AA plus prednisone compared to prednisone alone following docetaxel. The primary toxicity of mineralocorticoid excess is manageable. The addition of low-dose corticosteroids to AA may be necessary for controlling symptoms of mineralocorticoid excess.