Every year about one million people worldwide are diagnosed with an adenocarcinoma of the stomach or esophagogastric junction (AEG). These tumors are among the most common causes of cancer-related deaths worldwide. Complete resection of the primary tumor in conjunction with radical lymphadenectomy is the only curative treatment for most tumor stages. The interdisciplinary approach depends on tumor stage; the surgical approach additionally on the exact tumor location and histological classification. While the risk profile and various epidemiological characteristics differ between AEG and stomach adenocarcinoma, these entities have similar precursor lesions and molecular alterations. Squamous cell carcinomas of the esophagus, however, differ in terms of etiology and molecular alterations, as well as in terms of therapeutic approaches; they therefore require a separate portrayal.