This two-arm randomized clinical study aimed to evaluate the efficacy and safety of neoadjuvant concurrent chemotherapy and letrozole in postmenopausal women with locally advanced breast carcinoma. One hundred and one postmenopausal women aged 50-83 years with pathologically proven locally advanced (clinical stage T3, T4 and/or N2, N3) breast cancer were randomly assigned to receive neoadjuvant chemotherapy alone (control arm, n = 51) or neoadjuvant chemotherapy concurrent with letrozole 2.5 mg (study arm, n = 50). Chemotherapy consisted of a median 4 (range 3-5) cycles of intravenous 5-fluorouracil 600 mg/m(2), doxorubicin 60 mg/m(2), and cyclophosphamide 600 mg/m(2), every three weeks. All patients subsequently underwent modified radical mastectomy approximately two weeks after the last cycle of chemotherapy. Pathologic complete response rates were 25.5% and 10.2% in the study and the control group, respectively (P = 0.049). Similarly, clinical complete response rates were 27.6% and 10.2% in the study and the control group, respectively (P = 0.037). In the subgroup analysis of hormone receptor-positive cases, the complete response rates were more prominent in study group compared with control group. Common treatment-related side effects such as nausea, vomiting, bone marrow suppression, and mucositis were similar in both groups, but hot flush was more prevalent in study group compared with control group (P = 0.023). The addition of letrozole concurrently with neoadjuvant chemotherapy provides a higher clinical and pathologic response rates with acceptable toxicity compared with chemotherapy alone in postmenopausal women with locally advanced sensitive breast cancer.