Follow-up after curative treatment of patients with gastrointestinal cancers aims to detect recurrent disease and to provide curative treatment to prolong overall survival if possible. This, however, has only been shown for colorectal cancers. Regular visits including testing of carcinoembryonic antigen and appropriate staging has been shown to enable curative treatment even in relapse. For other gastrointestinal cancers, positive effects of regular follow-up visits on survival have not been shown so far. This is mostly also due to lacking curative treatment strategies in case of relapse. In these cases, follow-up is recommended for providing palliative treatment, detecting recurrence for quality issues, treating complications or symptoms due to relapse, and providing psychological support. This review will give a brief overview about the current follow-up issues in colorectal, esophagogastric, and pancreatic cancers, as these are clinically the most relevant.