The purpose of this study was to evaluate the efficacy and tolerance of combined treatment with docetaxel-cisplatin as first-line chemotherapy in patients with metastatic breast cancer (MBC). Consecutive eligible chemonaive patients received docetaxel 75 mg/m(2) on day 1 and cisplatin 75 mg/m(2) on day 2 every 3 weeks for 6 cycles, with prophylactic recombinant human granulocyte colony-stimulating factor (rHuG-CSF) on days 4-11. Thirty-two patients (64%) had received prior adjuvant chemotherapy; these included 16 (32%) who had received anthracyclines. In 50 evaluable patients with a median age (range) of 56 (31-72) years, the overall response rate was 68% (95% CI, 55-81%), with 7 (14%) complete and 27 (54%) partial responses. Stable and progressive disease was observed in 10 (20%), and 6 (12%) patients, respectively. The median duration of response was 10 months, and the median time to progression was 39 weeks. Grade 3/4 hematological toxicity included--neutropenia in 9 patients (18%), anemia in 2 (4%) and thrombocytopenia in 1 (2%). One patient (2%) with febrile neutropenia required hospitalization. Grade 3/4 nonhematological toxicities included nausea/vomiting in 18%, nephrotoxicity in 14%, asthenia (4%), and neurotoxicity (2%). Toxicity was common in older patients (>56 years). There were no treatment-related deaths. A combination of docetaxel-cisplatin with rHuG-CSF support is well tolerated and effective as first-line chemotherapy in MBC.