The advent of sentinel lymph node mapping (SLNM) has had a profound impact on the surgical management of breast cancer and melanoma over the past decade. However, SLNM in gastrointestinal malignancies is still in its infancy. The role of SLNM in gastrointestinal malignancies is to increase staging accuracy and to reduce the understaging associated with standard surgical and pathological techniques. Numerous authors have described the successful use of SLNM in colon, rectal, gastric, esophageal, and anal canal malignancies, with a high degree of accuracy and upstaging by detailed pathological analysis of the sentinel nodes. Over the past 2 years, research and publications related to gastrointestinal lymphatic mapping have dramatically increased worldwide.