Goserelin (Zoladex), a gonadotropin-releasing hormone analogue, reduces plasma/serum estrogen levels in pre- or perimenopausal women (to postmenopausal levels), and is indicated in hormone receptor-positive early breast cancer in this population group. Adjuvant goserelin monotherapy has similar efficacy to adjuvant chemotherapy in pre- or perimenopausal women with early, hormone receptor-positive breast cancer. Furthermore, the addition of goserelin to adjuvant chemotherapy appeared to offer an advantage over chemotherapy alone in younger patients. Fewer patients remained amenorrheic after goserelin therapy than after chemotherapy. Complete endocrine blockade provided by the addition of tamoxifen to therapy including goserelin appears to improve outcomes. Thus, goserelin offers a valuable addition to the currently available options for treating pre- or perimenopausal women with hormone therapy-responsive early breast cancer, particularly for women wishing to regain ovarian function after treatment.