Background: FOLFOX and XELOX are standard adjuvant chemotherapy for resected stage III colon cancer. MOSAIC and XELOXA trials were performed outside of Japan, thus, we conducted a phase II study (NORTH/HGCSG1003) to assess the efficacy and safety of FOLFOX as adjuvant chemotherapy for Japanese patients(pts) with resected stage III colon cancer (UMIN ID: 000004590). Methods: This phase II study enrolled patients with resected stage III colon cancer. Patients received 12 cycles of FOLFOX4 or mFOLFOX6. Sample size was determined to be 243 pts. Primary endpoint was disease-free survival (DFS). We assumed an expected 3-year DFS rate of 81.2% in this study. Secondary endpoints included overall survival (OS) and safety. In this meeting, we present for the 3-year DFS rate. Results: From Sep 2010 to Mar 2013, 273 pts were enrolled at 28 institutions. Full analysis included 265 patients who received FOLFOX. Patients characteristics were as follows: median age ; 65(33-84), Male/female ; 131/134, PS 0/1 ; 258/7, stage IIIA/IIIB/IIIC ; 37/197/31, colon/rectosigmoid: 214/51. The most common grade 3-4 adverse events were neutrophil count decreased (48.1%), peripheral sensory neuropathy (6.4%), platelet count decreased (2.3%), and allergic reaction (1.5%). The median number of cycles of FOLFOX was 12, and the completion treatment rate was 80.4%. There was no treatment-related death. The 3-year DFS rate was 75.2 percent (95% confidence interval, 69.6 to 80.0). Conclusions: In Japanese patients with stage III colon cancer, FOLFOX is a well-tolerable regimen as adjuvant chemotherapy. In this trial, the 3-year DFS rate of primary endpoint was not meet the expectation (81.2%). However, the 3-year DFS rate in this trial was similar to several pivotal trials. We plan to do subset analysis. Clinical trial information: UMIN000004590.