Gastrointestinal (GI) malignancies (esophageal, gastric, pancreatic, intra- and extra-biliary ductal, hepatocellular, and colorectal cancers) are an important cause of cancer incidence and mortality in the US and globally. GI cancers account for 15.4% and 23.8% of incident cancers and cancer-related deaths respectively in the US alone. Although earlier diagnosis and treatment advances have improved outcomes for some GI malignancies, the need for improved therapies in all disease phases (adjuvant, neoadjuvant and advanced) is paramount. Utilization of monoclonal antibodies targeting against vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) has shown the success in selected colorectal carcinoma patients. More investigations of immunotherapy are on going in the treatment of GI malignances with different mechanisms and methods. In this article, we review data for established and evolving immunotherapy-related treatment options in GI malignancies.