The purpose of this study was to evaluate the efficacy and safety of Zoladex combined with CEF chemotherapy as neoadjuvant therapy in hormone-responsive, premenopausal, operable breast cancer. One hundred and nineteen patients with hormone-responsive, premenopausal, operable breast cancer were enrolled in the study. Zoladex at 3.6 mg was given by subcutaneous injection every 4 weeks for 3 cycles. CEF (cyclophosphamide, 600 mg/m(2), epirubicin, 60-90 mg/m(2), and fluorouracil 500 mg/m(2)) was administered every 3 weeks for 4 cycles as neoadjuvant therapy. The primary objective was a pathologic complete response (PCR) rate in the breast. Thirty-one patients (26.1%) achieved a clinical complete response, and 76 patients (63.9%) achieved a clinical partial response; the clinical response rate was 90.0%. Fourteen patients (11.8%) achieved a pathologic complete response (T0/Tis, N0), and 20 patients (16.8%) achieved a pathologic complete response (T0/Tis, Nx). When stratified by the clinical lymph node status, the clinical partial response rate in the clinical lymph node negative group was significantly higher than in the clinical lymph node positive group (P = 0.02). When stratified by hormonal status, the clinical partial response rate in the ER and PR + group was significantly better than the ER or PR- group (P = 0.0471). There were no treatment-related deaths and no grades 3 or 4 toxicity. The most common adverse event was nausea (grade 1 65.5%, grade 2 18.5%), vomiting (grade 1 58.8%, grade 2 13.4%), and alopecia (grade 1 45.4%, grade 2 54.6%). Zoladex combined with CEF chemotherapy was effective as neoadjuvant therapy in hormone-responsive, premenopausal breast cancer. This regimen was particularly effective in the clinical lymph node negative group and in the ER/PR double positive group. (ClinicalTrials.gov number, NCT00488722).