Colon cancer is a leading cause of cancer and cancer deaths in Western countries. Although 5-fluorouracil is still the basis of adjuvant therapy, advances in drug development have led to increased efficacy with the addition of oxaliplatin and options for oral therapy with capecitabine. The benefit of adjuvant therapy for stage II disease is consistently small and not statistically significant. Future studies will evaluate the role of the biologic agents that have proved to be effective in metastatic disease and better delineate the population at risk by identifying prognostic and predictive markers.