Megaesophagus is a disorder of the esophagus characterized by diffuse dilation and decreased peristalsis. It is classified into congenital and acquired forms. Gastrointestinal, endocrine, immune-mediated, neuromuscular, paraneoplastic, and toxic disorders have been associated with acquired megaesophagus. Common clinical signs of megaesophagus are regurgitation, weight loss, coughing, and halitosis. Most cases of megaesophagus can be diagnosed using thoracic radiography; however, diagnosing the underlying cause requires a thorough history and additional diagnostics. The treatment, management, and prognosis of megaesophagus vary greatly depending on the underlying cause.