Many years ago, it was proposed that the symptoms of heartburn correlated more closely with acid-induced esophageal motility abnormalities than with the presence of inflammation. This concept, however, has not been evaluated by modern manometric techniques. We monitored intraesophageal pressures during acid perfusion (0.1N hydrochloric acid) in 17 reflux patients with gross esophagitis and positive pain response and 17 age-matched controls. Using a low-compliance infusion system, amplitude, duration, velocity, and the presence of simultaneous and repetitive contractions in the body of the esophagus were evaluated. Amplitude did not change in either group. Duration did increase significantly during acid perfusion in reflux patients, but not in controls. Mean duration between groups, however, was similar before and during acid perfusion. No simultaneous contractions were observed, while three patients and two controls had repetitive contractions. A significant decrease in velocity was observed in both groups during acid perfusion. These studies indicate that acid-induced motor abnormalities are neither a common accompaniment nor necessary for the production of acid-induced pain in the esophagus.