In 17 patients with esophagitis (degree I = erythema, N = 10; degree II = erosions, N = 7) esophageal pH was measured at 5 and 10 cm above the esophagogastric junction to assess whether the extension of acid reflux and the severity of the mucosal lesions could influence the association between reflux and symptoms. A minority of the refluxes were related with symptoms (4.0% and 7.7% in degree I, 14.1% and 12.0% in degree II at 5 and 10 cm respectively), whereas 65.4% and 100% of the symptoms were related with reflux in degrees I and II, respectively, with 76.5% and 35.7% occurring during refluxes reaching the proximal recording site. A relationship of symptoms with reflux is shown, particularly in erosive disease. Some reflux characteristics (extension, duration, acidity) seem to influence symptom occurrence mainly in mild esophagitis; however, more than 85% of the acid reflux episodes are symptom-free, regardless of the severity of the mucosal injury.