Introduction: It is generally thought that esophageal motility decreases with age, however a decrease in esophageal motility may also be caused by esophagitis. The aim of this study is to investigate the effects of aging and acid reflux on esophageal motility. Methods: 40 young (under 45) healthy subjects (HS) and 40 elderly (over 65) HS, with neither reflux symptoms nor reflux esophagitis (RE), and 40 elderly patients with mild RE (elderly RE), underwent esophageal high resolution manometry with a 21-lumen perfused assembly, which monitored pressure in the pharynx, the upper esophageal sphincter, the esophageal body, the lower esophageal sphincter (LES) and the proximal stomach. An infusion port, located 18cm above the distal side hole, was used to inject air and expiratory basal LES pressure was referenced to end expiratory intragastric pressure. Primary peristalsis was tested with 5ml water swallows, each swallow separated by a 30 second interval and the process repeated 10 times. Secondary peristalsis was triggered by esophageal distention, using a 20ml bolus of air, which was injected rapidly, by hand, into the middle esophagus. After 20 seconds each stimulus was followed by a dry swallow to clear any of the residual air and then repeated 5 times. Results: There was no difference in the LES pressure and also in the success rate of primary peristalsis between young and elderly HS or between elderly HS and RE. There was no difference in the distal contractile integral (DCI) of primary peristalsis and secondary peristalsis between the young and elderly HS, but in the elderly RE, it was significantly lower than in the elderly HS. There was no difference in the success rate of secondary peristalsis between elderly HS and RE, but in elderly HS it was significantly lower than in young HS. Conclusion: Aging may cause a decrease in the success rate of secondary peristalsis, and acid reflux itself may cause a decrease of the DCI in primary and secondary peristalsis.