BACKGROUND: Metastatic breast cancer is a systemic disease, and its treatment aims at the palliation or cure of the disease. In recent years, good results have been reported in the treatment of metastatic breast cancer by using single-agent paclitaxel chemotherapy. METHODS: We performed a retrospective study by analyzing the medical records of patients treated at Kangnam St. Mary's Hospital between May 1995 and May 1997. A total of 29 patients with metastatic breast cancer were treated by a 135-mg/m2, 3-hour infusion of paclitaxel. The results were reviewed with respect to the response rates and the toxicities of paclitaxel. RESULTS: The overall response rate was 13.8%: CR (complete response rate) 3.4% (1 out of 29) and PR (partial response rate) 10.3%(3 out of 29). The most common and severe toxicity was leukopenia. However, there was no mortality, and the patients were tolerated this therapy. CONCLUSIONS: Paclitaxel as a single-agent therapy for metastatic breast cancer is tolerable, but less effective, than reported.