Esophageal, gastroesophageal junction, and gastric cancers are underpublicized but are frequently lethal, and gastroesophageal junction adenocarcinomas are increasingly common diseases in the United States and around the world. Although often grouped together in studies of chemotherapy, clear distinctions can be made in the locoregional therapy of these diseases. Esophageal squamous cell carcinomas may be treated with surgery or radiation with concurrent chemotherapy, whereas esophageal adenocarcinomas and gastroesophageal junction adenocarcinomas are often treated with all three treatment modalities. Over the past several years, it has become increasingly evident that gastric cancer is a disease that is potentially sensitive to chemotherapy. In the perioperative settingat least in the Western worldchemotherapy and sometimes radiation are applied. However, the optimal chemotherapy for advanced gastric or esophageal cancer remains unsettled, and there is no single standard regimen. Several new chemotherapy agents have demonstrated activity in these diseases, but the best chemotherapy remains to be determined. This paper will review the role of chemotherapy in gastroesophageal cancers.