Docetaxel (Taxotere) and doxorubicin have previously demonstrated a significant antitumor activity in patients with metastatic breast cancer. Furthermore, a lack of cross resistance and overlapping toxicities between the two agents have been reported. In a prospective study, docetaxel (80 mg/m2, 1-hr iv infusion) and doxorubicin (60 mg/m2, 1-hr iv infusion) were administered as first-line chemotherapy in metastatic breast cancer patients to evaluate the clinical efficacy and toxicity of the combination. Forty-three patients were enrolled in the study. The median age was 47 years (range, 30-69). The docetaxel-doxorubicin combination was applied with 3-week intervals until progression. Complete response was achieved in 9 (21.4%) of 42 assessable patients and partial response in 24 (57.2%) patients, for an overall response rate of 78.6%. Median response duration was 8 months (3-18 months). Nausea and vomiting (76%), alopecia (64%), neutropenia (35.7%) and mucositis (33%) were the major side effects of the combination. There was one case of cardiac toxicity. In conclusion, the docetaxel-doxorubicin protocol can be considered as an active regimen for the treatment of patients with metastatic breast cancer with acceptable toxicity and a fairly high response rate.