Fulvestrant ('Faslodex') is a new type of estrogen receptor antagonist with no agonist effects, that reduces cellular levels of both estrogen and progesterone receptors. Results from two Phase III trials showed that fulvestrant is at least as effective as the third-generation selective aromatase inhibitor anastrozole in postmenopausal women with advanced breast cancer following progression on antiestrogen therapy, indicating the potential for second-line fulvestrant in this setting. In clinical practice, fulvestrant is well tolerated, with good rates of clinical benefit observed as first-line therapy and following progression on prior endocrine agents. Other endocrine agents have been shown to have good clinical activity when resistance to fulvestrant has developed, showing that fulvestrant lacks cross-resistance with other treatments. Ongoing trials are investigating the efficacy of fulvestrant after failure on aromatase inhibitors and evaluating its use in combination with therapies that target growth factor receptor signaling pathways.