Our department recently began using paclitaxel in treating patients with breast cancer. Retrospective analysis was conducted to clarify its clinical usefulness. Forty-one patients with metastatic breast cancer were treated with paclitaxel between November 2000 and September 2002. Hospital records of the patients, except for one unsensored patient, were retrospectively reviewed. Characteristics of the patients were as follows: age, 36-81 Y (median, 56); 8 stage IV and 32 recurrent diseases; most frequent dominant site of metastasis was the liver (22 patients, 55%); number with previous chemotherapy was 0-5 (median, 2); anthracycline-based treatment and docetaxel treatment were previously performed in 21 (53%) and 15 (38%) patients, respectively; weekly dose of paclitaxel was 30-150 mg/body (median, 100); and total dose administered was 600-6, 480+ mg/body (median, 1,820). Objective response and clinical benefit rates were 35% and 80%, respectively. Median duration of response, time-to-progression and overall survival were 27+, 33+ and 41.5 weeks, respectively. Common adverse events were sensory neuropathy (45%) and nausea/vomiting (37.5%). Most were graded as 1 or 2. Various agents, such as hormonal agents and trastuzumab, were administered with paclitaxel in 26 patients (65%). No significant difference was observed in efficacy or toxicity among patients treated with paclitaxel alone or paclitaxel plus other agents. Paclitaxel seems to be a feasible, safe and active agent for patients with metastatic breast cancer.