This study was designed to evaluate the efficacy and tolerability of a weekly schedule of epirubicin in combination with docetaxel in the first-line treatment of patients with metastatic breast cancer (MBC). A total of 43 women with MBC not previously treated with chemotherapy for metastatic disease received weekly epirubicin 25 mg m(-2) and docetaxel 25 mg m(-2) for a maximum of five cycles (total cumulative epirubicin dose of < or =900 mg m(-2)). Dose reduction was not permitted. Objective response and evaluation of toxicity profile were the primary study end points; time to progression and overall survival were secondary end points. Patients were followed for a median of 21 (4-38) months. Analysis was by intent to treat; 33 patients completed five cycles of therapy, and the median dose of epirubicin administered to the 43 patients was 23 mg m(-2). Twenty-five patients (58%) achieved a partial response and one (2%) achieved a complete response. An additional 12 patients (28%) had stable disease. The median time to progression was 11 months (95% confidence intervals (CI) 7-14) overall, and 13 months (95% CI 12-14) in the 26 patients who responded to treatment. Median overall survival was 25 months for responders and 14 months for nonresponders. Grade 3/4 neutropenia occurred in 16% of patients and in 6% of cycles. One patient developed cardiac toxicity (20% reduction in left ventricular ejection fraction). The combination of epirubicin plus docetaxel is highly active in MBC, with a manageable toxicity profile. Such a weekly schedule might provide a valuable treatment option for MBC.