Hepatectomy has the highest cure rate among the various methods for treating liver metastasis from colorectal cancer. We previously reported that continuous hepatic arterial infusion (HAI) of 5-FU is effective for improving the prognosis of patients with liver metastasis. In this study, we examined the efficacy of short-term continuous HAI of 5-FU for treating liver metastasis from colorectal cancer. A 57-year-old woman with a solitary liver metastasis from rectal cancer was treated by continuous HAI of 5-FU (1,000 mg/day) for 6 days. Her elevated serum CEA level (20.7 ng/ml) then returned to normal. Computed tomography revealed a decrease of 55.6% in the size of the liver tumor. Partial segmentectomy (S7) was subsequently performed. Histological examination of the resected tumor showed marked degeneration, necrosis, fibrosis, and calcification with viable moderately differentiated adenocarcinoma cells. These results suggest that preoperative HAI of 5-FU is safe and worth trying in patients with liver metastasis from colorectal cancer.