BACKGROUND: To know whether the laryngeal mask airway (LMA) triggers a pharyngo-esophago- gastric reflex during general anesthesia, we compared the esophageal motility of patients with an LMA or endotracheal tube (ETT) in place. METHODS: Fifty patients (ASA I or II) scheduled for elective orthopedic surgery with general anesthesia were randomly allocated into LMA (n = 30) or ETT (n = 20) groups. The esophageal manometric inputs were recorded continuously using an ambulatory esophageal manometric recorder and divided into five perioperative phases (preanaesthesia, induction, operation, LMA or ETT rejection, and arousal phase). RESULTS: The peristaltic percent and number of contractions per minute were significantly decreased during induction, operation, LMA or ETT rejection and arousal phases compared with preanesthetic phases in both the LMA and ETT groups. However, there were no significant group differences in any corresponding perioperative phases. CONCLUSIONS: We suggest that during general anesthesia the use of a LMA does not provoke significantly different esophageal peristalsis compared with an ETT. Thus, the LMA is unlikely to potentiate gastric regurgitation and reflux during general anesthesia by stimulating the pharyngo-esophago-gastric reflex.