The optimal postoperative follow-up strategy for patients with resected Dukes' Stage B and C colorectal cancer is controversial. Recently published guidelines support a minimal regimen of carcinoembryonic antigen measurements every 2 to 3 months for at least 2 years, history and physical examination every 3 to 6 months for 3 years, then annually, and colonoscopy every 3 to 5 years. Based on documented practice on the part of surgeons, this regimen would be regarded as intensive. Analyses of relapses following adjuvant therapy support an even more aggressive schedule, with the goal of maximizing the proportion of patients who may be operated on with curative intent (currently about 20% of those who relapse). Additional considerations that may influence the approach to such patients include the identification of second primary tumors (2% over 7 years observation), and the known improvement in quality of life and survival associated with early versus delayed initiation of chemotherapy. However, with the annual investment of resources estimated to be as high as 175 million dollars in the United States alone, a systematic study of such interventions is needed to provide support survival, quality of life, and economic evidence.