We report a case of rectal cancer with unresectable multiple liver metastases, which was worried about the transition from liver dysfunction to liver failure. The male patient in his 70s was diagnosed as advanced rectal cancer with severe liver dysfunction because of multiple liver metastases. Hepatic arterial infusion (HAI) chemotherapy, which was effective to reduce the size of metastatic liver tumors, was initially started. During HAI chemotherapy, sigmoid colostomy was performed. He recovered from liver dysfunction after he had been treated with 13th cycle HAI chemotherapy. He was treated with the modified FOLFOX6 regimen following a resection of rectal cancer. Although the standard therapy for colorectal cancer with unresectable liver metastases is firstly systemic chemotherapy such as FOLFOX or FOLFIRI, it might be better to control the liver metastases by HAI chemotherapy when a liver function is severely damaged by extensive liver tumors.