In February, 19 9 8, a 48-year-old female patient underwent an operation for breast cancer. In November 2003, abdominal MRI revealed metastatic lesions in S 3 and S 5 of the liver, and chemotherapy (trastuzumab+weekly paclitaxel) was started, after which the metastatic lesions quickly reduced in size. No lesions could be detected by April 2004, and she was diagnosed as a complete response (CR). She now visits our hospital as an outpatient without any evidence of recurrence or any side effects of chemotherapy for 8 years and 8 months after surgery. For advanced breast cancer, there is no standard criteria regarding the time when to stop chemotherapy after obtaining a CR. This time, we experienced a case of liver metastasis of breast cancer responding to a regimen of trastuzumab plus weekly paclitaxel chemotherapy maintaining CR for a long period. We discuss the timing of the termination of chemotherapy in such a case in light of our experience and the literature.