As an adjuvant treatment for Dukes B2 and C colon cancer, adding oxaliplatin (L-OHP) to a regimen of fluorouracil and Leucovorin improved disease-free survival in Western countries. In Japan, however, adjuvant chemotherapy with L-OHP is not commonly used to treat Stage III colon cancer. We report the present condition of adjuvant treatment for colon cancer in our hospital. Between September 2009 and December 2011, 66 patients with Stage III colon cancer were enrolled after curative surgery. The details of adjuvant therapy with fluoropyrimidines with and without L-OHP were explained to the patients. After the explanation, 33.3% of the patients(IIIa: 18.9%, IIIb: 55.5%) selected L-OHP chemotherapy. Regardless of the side effects, adjuvant chemotherapy including L-OHP is expected to protect against cancer recurrence in patients with Stage IIIb colon cancer.