5-Fluorouracil(5-FU)and cis-dichlorodiammineplatinum(CDDP)combined with 60Gy of radiation was administered to a 65-year-old man with advanced esophageal cancer complicated with chronic renal failure treated with hemodialysis(HD). Continuous infusion of 5-FU 680mg/m(2) on Days 1-5 and 8-12, and drip infusion of CDDP 40mg/m(2) on Days 1 and 8 were administered twice with a 5-week interval. The CDDP dosage was reduced to 40% and HD was started 30 minutes after CDDP administration. Concurrent radiotherapy was started on Day 1 at 2Gy/d for 5d/week. The concentration of both free CDDP and total CDDP was measured using the atomic absorption method after the second treatment period. The area under the curve(AUC)of free CDDP was 3.3microg x h/ml. Both Grade 4 anemia and Grade 3 leukopenia were observed, but the renal failure did not progress. All toxicities were tolerable and the CDDP dose reduction and HD method were appropriate for the patient.