A 36-year-old woman was referred to our hospital because of a right breast lump. Chest computed tomography revealed pulmonary metastases with lymphangitis carcinomatosa. Additional examination revealed liver metastases and axillary and cervical lymph node metastases. The patient was started on CA therapy (cyclophosphamide 900 mg, adriamycin 90 mg). A minor response was observed in the pulmonary metastases after two courses but new brain metastases were detected. We then tried paclitaxel administration (260 mg). A partial response was observed in the brain and pulmonary metastases. Thus, paclitaxel administration was continued on a weekly basis (120 mg) and the brain and pulmonary metastases continued to diminish. The primary breast cancer, liver metastases and axillary and cervical lymph node metastases were disappeared. Whole brain radiation was done with weekly paclitaxel administration and the brain metastases were diminished even more. Paclitaxel is as a radiosensitizer and seems to have a strong antineoplastic effect with concurrent radiation.