The acute effects of oral metoclopramide (40 mg/day) and domperidone (80 mg/day) on esophageal motor activity and acid reflux were assessed in a randomized, double-blind, placebo-controlled study in 20 patients with erosive reflux esophagitis. Esophageal motor function was assessed by standard manometry with wet swallows, and reflux events were evaluated by ambulatory 24-hr pH-monitoring. Both drugs caused a significant (P less than 0.05) increase in lower esophageal sphincter pressure lasting at least 120 min. However, neither esophageal body motility, duration of esophageal exposure to acid, nor esophageal clearance were effected by drug administration in comparison to placebo. Side effects were reported in two patients who received metoclopramide, while no adverse effects occurred after domperidone intake. In conclusion, the so-called motility agents metoclopramide and domperidone have few acute effects on esophageal motility in patients with erosive reflux esophagitis.