Seventeen patients with unresectable liver metastases from colorectal cancer were treated with 5 hour infusion of 1,000 mg/m2 of 5-FU in weekly schedule, employing a newly developed portable pump "Koken-Infusor". This pump is operated by batteries. It is small, light and easy to use. And five hundred cycles of treatments were performed, but the pump induced no major complications. The response evaluated by a CT-scan was 73% (11/15) without major toxicities. In conclusion "Koken-Infusor" is very useful for this treatment, especially for out patients. It appears that this therapy is one of the effective treatments for liver metastases from colorectal cancer.