In 2009, the projected incidence for colon and rectal cancers in the United States was 106,100 and 40,870, respectively, and approximately 75% of these patients were treated with curative intent. Surveillance or follow-up after colon and rectal cancer resection serves multiple purposes; however, the primary argument supporting the validity of surveillance is the detection of metachronous and recurrent cancers amenable to curative treatment. The surveillance may provide some comfort for cancer survivors who can be informed that they have no evidence of disease.