Breast cancer is the most common type of cancer in women worldwide. In Mexico, >34% of patients are in locally advanced stages at the time of diagnosis. Neoadjuvant chemotherapy is administered to control local disease, make surgical resection possible and increase the possibility of breast tissue conservation. We performed a double-blind, randomized clinical trial in patients with locally advanced breast cancer (stages IIB and IIIA) with two therapy schemes; 5-fluorouracil-epirubicin-cyclophosphamide (control group) vs. docetaxel-epirubicin (study group). Both were indicated in three preoperative cycles, and patients were submitted afterwards to surgery. Pathological response was measured. Forty one patients were included in our study. They were distributed in two homogeneous groups: 21 in the control group and 20 in the study group. Dimensional pathological response was higher in the study group than in the control one (p