Patients with hormone receptor-positive tumors less often show a pathological complete response (pCR) than do those with hormone receptor-negative tumors. The addition of endocrine therapies may improve the clinical benefits of primary therapies in these patients. We investigated the efficacy of the epirubicin+cisplatin+fluorouracil (ECF) as continuous infusion) regimen in association with a gonadotropin-releasing hormone (GnRH) analog in 36 premenopausal women with T2-T4a-d N0-2 M0 ER and/or PgR-positive breast cancer. Median age was 39.5 years (range 26-53). Clinical response (complete or partial) was observed in 27 out of 36 patients (75% 95% CI 57.8-87.9%) and a pCR was observed in four patients (11%). Nine (25%) patients had stable disease and no progression was observed. Twenty-one patients (58%) were submitted for breast-conserving surgery and 15 had a radical mastectomy. No baseline clinical and biological characteristics significantly correlated with response. Thirty out of 31 patients evaluable for endocrine assessment had documented ovarian suppression, which occurred after a median of 28 days (range 20-43). We conclude that the combination of ECF and a GnRH analog is associated with a high response rate in the primary treatment of breast cancer. Further studies combining chemotherapy and endocrine agents are warranted in patients with hormone receptor-positive tumors.