Twenty-eight patients received Taxol as their first chemotherapy for stage IV breast cancer. An additional 51 patients with extensive prior exposure to other chemotherapeutic agents received Taxol as salvage therapy. We found significant activity for the drug in both situations, as well as a strong clinical suggestion of non-cross-resistance with doxorubicin. An excellent response in previously irradiated skin was noted in one case. The routine use of recombinant human granulocyte-colony stimulating factor seemed to ameliorate some of the dose-limiting toxicity of neutropenia. Other toxicity was mild to moderate in most cases. With further development, Taxol should play a significant role in the systemic management of breast cancer.