Current methods to evaluate patients with esophageal disease include barium swallow with fluoroscopy, which is useful in demonstrating structural defects. Disordered motility is better evaluated with a cine-esophagram. Recent application of radioisotopes has been useful in evaluation of esophageal reflux and the post-treatment of achalasia. Esophageal motility studies may evaluate lower esophageal sphincter and upper esophageal sphincter pressures and the response of the body of the esophagus to series of swallows. Since there is no "gold standard" for the evaluation of reflux esophagitis, some of the tests designed to evaluate reflux and the patient's reaction to acid in the esophagus include the acid infusion test, the standard acid reflux test, the acid clearance test, and 24-hour pH monitoring. Endoscopy with either the flexible or the rigid instrument is important for the diagnosis of obstruction or esophagitis and allows direct visualization of the esophagus. The treatment of reflux esophagitis is discussed. The differential diagnosis of dysphagia may include achalasia, diffuse esophageal spasm, and mechanical obstruction of the esophagus due to rings, webs, strictures, and benign or malignant tumors. The evaluation of dysphagia should include radiologic as well as endoscopic evaluation. Treatment of obstruction varies according to the nature of the lesion. The Mallory-Weiss syndrome or bleeding from the mucosal tears of the gastroesophageal junction and Boerhaave's syndrome, spontaneous esophageal perforation, are two disorders associated with vomiting. The Mallory-Weiss syndrome usually resolves without specific therapy, but a high index of suspicion is required for patients with chest pain after vomiting, as spontaneous perforation necessitates immediate surgery. Most diverticula need no treatment, but the Zenker diverticulum, if symptomatic, should probably be surgically repaired.