Fulvestrant is an estrogen receptor antagonist indicated for the treatment of hormone receptor-positive metastatic breast cancer (MBC) in postmenopausal women with disease progression following antiestrogen therapy. Fulvestrant has a different mechanism of action than other hormonal therapies, including aromatase inhibitors and tamoxifen. In clinical trials of postmenopausal women with MBC, fulvestrant was effective and well tolerated compared to anastrozole after failure of tamoxifen. The monthly injection regimen of fulvestrant provides nurses with an additional opportunity to improve patient adherence to hormonal therapy, reinforce patient education, and monitor side effects. Several ongoing trials will elucidate the role of fulvestrant in the treatment of MBC. Issues that are being addressed in those trials include alternative doses and schedules, efficacy and safety in other patient populations, and the development of novel treatment combinations. This article provides oncology nurses with the knowledge needed to educate patients on the use of fulvestrant, to effectively administer this medication, and to prevent and manage potential side effects.