In July 2003, a 59-year-old man underwent a right hemicolectomy for sigmoid colon cancer. Hepatic intraarterial injection therapy with 5-FU/CDDP was not only ineffective against a liver metastasis but a lung metastasis was also found, and therefore systemic chemotherapy with CPT-11/5-FU/l-LV (IFL) was administered. After onetime IFL therapy, the CPT-11 was withheld due to ileus. Although 5-FU/l-LV therapy was administered, it was ineffective. IFL therapy was again performed, with the dose decreased by 20%, as part of ambulatory treatment. Not only the liver metastasis but also the lung metastasis decreased significantly in size after one course. In addition, no severe adverse reactions were observed during the treatment, which enabled the therapy to be continued as part of an ambulatory regimen. The results suggest that IFL therapy is effective against colon cancer with lung/liver metastasis and can be administered as part of ambulatory treatment.