Diseases of the gastrointestinal tract may result in radiographic changes in the thorax. An abnormal chest radiographic finding is often the initial clue to the diagnosis of gastrointestinal disease. This article presents the commonly recognized and some unusual thoracic manifestations of significant primary esophageal diseases including achalasia, diverticula, carcinoma, duplication cysts, varices, esophageal perforation, and postoperative changes. Intraabdominal gastrointestinal processes such as pancreatitis or pseudocysts, gastric and colonic abnormalities, pneumoperitoneum, liver abnormalities, intraabdominal abscesses, and diaphragmatic hernias, which are frequently associated with intrathoracic abnormalities, are also reviewed. Awareness of changes on the chest radiograph produced by gastrointestinal disease allows prompt diagnosis and facilitates the appropriate confirmatory diagnostic study, such as esophagography or computed tomography.