The development of miniaturized electronic pressure transducers and portable digital data recorders with large storage capacity has made ambulatory monitoring of esophageal motor function over an entire circadian cycle possible. Broad clinical application of this new technology in a large number of asymptomatic normal volunteers and patients with symptoms suggestive of a primary esophageal motor disorder provides new insights into esophageal motor function under a variety of physiologic conditions in health and disease. These studies suggest that ambulatory esophageal motility monitoring allows for a more precise classification of esophageal motor disorders than standard manometry and can identify abnormal esophageal motor patterns associated with nonobstructive dysphagia or noncardiac chest pain. Ambulatory esophageal motility monitoring performed in combination with pH monitoring is currently the most physiologic way to assess esophageal function and has potential to improve diagnosis and management of patients with esophageal motor disorders. Ambulatory 24-h esophageal motility monitoring should become the gold standard for assessing motor function of the esophageal body.