The standard chemotherapy regimen for esophageal cancer is cisplatin and 5-fluorouracil (5-FU). We herein report a case of esophageal cancer associated with colon cancer, which was treated with combination chemotherapy of FOLFOX. The patient received chemotherapy of modified FOLFOX6 (mFOLFOX6) at dosages of 80% of standard regimen (oxaliplatin 68 mg/m2, levofolinate calcium 160 mg/m2, bolus 5-FU 320 mg/m2, and followed by continuous 5-FU 1,920 mg/m2/ 46 hr) in combination with radiotherapy (total 61.6 Gy). He developed grade 3 leukopenia after 2 courses of mFOLFOX6 and the 3rd course was started at dosages of 70% of standard regimen with 1 week delay. After that, no other adverse event without grade 2 esophagitis was appeared. Esophagogram revealed a partial response in primary tumor of the esophagus after 3 courses of chemotherapy with radiotherapy and blood chemistry examination showed negative squamous cell carcinoma antigen. One month after chemoradiotherapy, esophagogram revealed tracheoesophageal fistula, but tumor of the esophagus was well controlled. FOLFOX regimen combined with radiotherapy is well tolerated and effective for inoperable esophageal cancer. FOLFOX cannot be used for esophageal cancer in Japan, so clinical trial of FOLFOX for esophageal cancer should be conducted in the near future in Japan.