Docetaxel (Taxotere) has been intensively investigated for the treatment of metastatic breast cancer, where it has proved to be one of the most active agents. Initial phase H studies in anthracycline-resistant metastatic breast cancer demonstrated impressive response rates that have been confirmed in phase III randomized trials. Docetaxel remains the only single agent to demonstrate a survival benefit in anthracycline-resistant patients. More recently, the combination of docetaxel with capecitabine (Xeloda) has demonstrated additional improvement in survival over docetaxel alone in a randomized phase III trial. In patients previously treated with an alkylating agent, docetaxel is the only single drug to demonstrate improved efficacy over doxorubicin in a randomized trial. Docetaxel has been investigated in combination with the anthracyclines doxorubicin and epirubicin in randomized trials. The docetaxel-containing regimens have consistently demonstrated improvement over the non-docetaxel-containing regimens. The efficacy and safety of weekly docetaxel has extended the line of investigation for combinations with agents normally administered on, a weekly basis, such as vinorelbine [Navelbine], gemcitabine [Gemzar], and trastuzumab [Herceptin], with promising findings. In addition, the results of the triple-drug combination of docetaxel, a platinum salt (cisplatin or carboplatin), and trastuzumab have resulted in impressive response rates and time to progression in a population of metastatic breast cancer patients with HER2/neu-positive tumors. The consistent demonstration of a high level of efficacy with manageable toxicity ensures the continued widespread investigation of docetaxel in metastatic breast cancer.