Fifty patients with histologically confirmed stage III breast cancer were enrolled in this study of doxorubicin 50 mg/m2 and docetaxel 75 mg/m2 intravenously infused over 1 hour every 21 days with granulocyte colony-stimulating factor for 4 cycles. This was followed by surgery (mastectomy or lumpectomy) and 4 more cycles of doxorubicin/docetaxel postoperatively, then radiation and tamoxifen as indicated. Forty-six of the 50 patients (92%) completed neoadjuvant chemotherapy, and 38 patients (76%) completed adjuvant chemotherapy. Clinical response (defined as > 50% decrease in size of tumor) was achieved after 2 cycles in 37 patients (74%) and after 4 cycles in 42 of the 46 patients (91%) who finished neoadjuvant chemotherapy. Pathologic complete response (pCR; no pathologic invasive cancer) at the primary site was obtained in 7 of 46 patients (15%); 11 had no residual gross disease but did have microscopic persistence or microscopic complete response (mCR), for a combined pCR and mCR of 18 of 46 patients (39%). No treatment-related deaths occurred, but 3 patients died during treatment: 1 from progressive disease, 1 from a gastrointestinal bleeding, and 1 from unexplained sudden cardiac death. Dose-limiting toxicities were hematologic (grade 3 neutropenia in 5 patients and grade 4 in 23 patients). Congestive heart failure developed in 4 of 50 patients (8%), with a mean decrease in left ventricular ejection fraction (LVEF) of 20% in affected patients and 1 asymptomatic decrease in LVEF of 25%. At last follow-up, 10 patients had died of progressive disease, and 1 each from sudden cardiac death and lower gastrointestinal bleeding. In locally advanced breast cancer, neoadjuvant doxorubicin/docetaxel is a very active regimen that achieved pCR of 15% and a combined pCR and mCR of 39%, for an overall clinical response rate of 91%. Adjuvant chemotherapy was complicated by dropouts and congestive heart failure. This regimen should be used with close monitoring of cardiac function.