The authors reviewed the liver histopathology and the clinical features of eight patients with liver metastases from colorectal cancer who were treated by hepatic arterial infusion chemotherapy (HAIC) via an implantable pump (Infusaid). Before HAIC, these patients had no evidence of hepatitis, and results of liver biopsies performed on three patients showed only minor morphologic alterations. All the liver tumors responded to HAIC, but all patients developed hepatitis. Clinical findings included nausea, vomiting, abdominal pain and jaundice. Serum transaminases, alkaline phosphatase and bilirubin levels were increased. Clinical observations suggested that 5-fluoro-2'-deoxyuridine (FUDR), the predominant drug given, was the hepatotoxic agent. Toxic effects were hepatocyte necrosis, steatosis, cholestasis, central vein sclerosis, and alterations in the portal triad. In addition, central vein lesions like those in veno-occlusive disease, and micronodular cirrhosis resembling that induced by alcohol, were encountered. Although individual susceptibility to FUDR appeared to vary, portal triad fibrosis was present in all eight cases and, together with central vein sclerosis and cirrhosis, appeared to be related to the dose and duration of HAIC.