A significant proportion of patients with colon cancer who undergo curative surgical resection develop metastatic disease. Over the last 20 years large prospective randomised studies have demonstrated a clear survival benefit for patients with stage III colon cancer who are treated with adjuvant 5FU based chemotherapy. At the present time 6 months of 5FU and leucovorin is generally considered the standard adjuvant therapy. For stage II disease the routine use of adjuvant treatment remains controversial. Newer drugs such as oxaliplatin, irinotecan, and the oral fluoropyrimidines have proven active in advanced colorectal cancer and are currently being evaluated in the adjuvant setting. Molecular markers for this disease are being identified and may help define those patients who would benefit from therapy. The integration of adjuvant immunotherapy with conventional chemotherapy offers the potential to improve the long-term outcome for surgically resected colon cancer.