One of the new agents intensively studied in the last decade for the treatment of metastatic breast cancer is vinorelbine (Navelbine; Burroughs Wellcome Co, Research Triangle Park, NC; Pierre Fabre Médicament, Paris, France). This vinca alkaloid produces response rates comparable to other single agents in women with metastatic breast cancer and is associated with a nonhematologic toxicity profile that makes it particularly advantageous for palliative treatment. In vitro studies provide evidence of the decreased neurotoxicity of vinorelbine compared with other vinca alkaloids and clinical studies document the drug's favorable toxicity profile. Granulocytopenia, the dose-limiting toxicity of this agent, is transient and, at current recommended dose levels, seldom results in life-threatening consequences. Results of a randomized clinical trial of intravenous vinorelbine show a similar or slightly improved effect on patient quality of life compared with intravenous melphalan (Alkeran; Burroughs Wellcome Co). Response rates in phase II trials of single-agent vinorelbine in women with previously untreated metastatic breast cancer range from approximately 30% to 60%. A number of studies are under way on the use of vinorelbine in combination with other agents commonly administered for the treatment of metastatic breast cancer. The low toxicity of vinorelbine makes it an attractive addition to several current combination regimens. Studies of increased dose intensity regimens of vinorelbine also are being actively pursued. Efforts to optimize the use of vinorelbine will hopefully lead to improved therapeutic options for the management of metastatic breast cancer.