We attempted a new regimen of low-dose CPT-11 on a 5-FU resistant recurrent rectal cancer patient with multiple lung metastases and a paraaortic lymph node metastasis. CPT-11 was administered at 25 mg/m2/day x 3/week by intravenous infusion. Serum CEA level decreased gradually with a half time of approximately 4 weeks. The lung metastases almost disappeared and the paraaortic lymph node was also reduced more than 50%. There were no adverse effects except slight alopetia. This treatment could be continued on an outpatient basis. These results suggest that low-dose CPT-11 may be more effective and tolerable than the conventional, CPT-11 therapy.