Ulipristal acetate (UPA; formerly known as CDB-2914) is a novel, high-affinity, selective progesterone receptor modulator that has low antiglucocorticoid activity, specifically developed by HRA Pharma for emergency contraception. In Phase I/II trials, UPA delayed ovulation in women when given in the mid-follicular phase and was as effective as levonorgestrel in preventing pregnancy after unprotected sex. Oral doses of UPA were absorbed rapidly and cleared slowly, and the side effects were apparently minimal. Recently, HRA Pharma have announced that ellaOne® (UPA) has been granted marketing authorization by the European Commission for emergency contraception within 120 h of unprotected intercourse. Herein, a careful review of the main existing papers was carried out, focusing on UPA as an emergency contraceptive agent. © 2010 Expert Reviews Ltd.