This study was designed to evaluate the antitumor activity and tolerance of biweekly docetaxel plus vinorelbine as first-line chemotherapy in patients with metastatic breast cancer (MBC). Forty-one patients with measurable disease and no prior chemotherapy for MBC were treated with docetaxel 60 mg/m(2) plus vinorelbine 30 mg/m(2) on day 1, every 2 weeks for a maximum of 12 courses. Median age was 58 years (range, 23-75). Fourteen patients (34.1%) were premenopausal and 27 (65.9%) were postmenopausal. Most patients had received prior neoadjuvant/adjuvant chemotherapy (n = 27, 65.9%), radiation therapy (n = 22, 53.6%), and hormone therapy (n = 21, 51.2%). The most frequent sites of metastasis were bone (n = 18, 43.9%), pleuropulmonary (n = 16, 39%), and liver (n = 14, 34.1%). Twenty-seven patients (65.9%) had more than one site of metastasis. Three hundred and thirty-nine courses were given (median, 8 courses per patient; range, 1-12). Median relative dose intensity was 85% for both docetaxel and vinorelbine. Grade 3/4 toxicities included neutropenia (14 patients, 34.1%), febrile neutropenia (n = 14, 34.1%), and stomatitis (n = 4, 9.8%). No treatment-related deaths were reported. All patients were assessed for response in an intent-to-treat analysis. Four patients (9.8%) had a complete response and 19 (46.3%) had a partial response (overall response rate, 56.1%; 95% CI, 42%-70%). Six patients (14.6%) had stable disease and 12 patients (29.3%) had progressive disease. With a median follow-up of 15.1 months or until death, median duration of response is 12.6 months. Median time to progression is 12.4 months. Median survival time is 19.6 months. This biweekly combination of docetaxel plus vinorelbine is feasible and active as first-line chemotherapy in patients with MBC. This regimen is safe and well tolerated.