In a single-center, open, phase II trial, we assessed the toxicity and activity of a triple combination therapy--doxorubicin at 30 mg/m2 (day 1), paclitaxel (Taxol) at 135 mg/m2 (day 2), and gemcitabine (Gemzar) at 2,500 mg/m2 (day 2 after paclitaxel)--administered biweekly in a 28-day cycle for six cycles. This was given as first-line treatment in 41 patients with metastatic breast cancer. Granulocyte colony-stimulating factor was used in 27 patients to permit maintenance of dose density. Hematologic toxicity was moderate. Nonhematologic adverse events were generally mild. The objective response rate was 82.9% (34/41) with 18 patients (43.9%) achieving complete response and 16 (38%) achieving partial response; progressive disease was observed in 4 patients (9.8%). Responses were observed at all metastatic sites, including complete responses in lung, liver, bone, and soft tissue. Median duration of response was 14.1 months and median time to progression was 13.9 months. Median survival was 26.2 months. The biweekly combination of gemcitabine, doxorubicin, and paclitaxel is safe and highly active as first-line treatment in metastatic breast cancer.