Background/Aims: The aim of this study was to evaluate acid clearance in esophageal disease, a common cause of noncardiac chest pain, and to evaluate the correlation between the swa]lowing number for acid clearance and the amplitude of contractions. Methods: The study population was divided into four groups. Group 1(n=8) was controls with no complaints of any gastrointestinal symptoms. Group II(n=9) was gastroesophagea1 reflux disease. Group III(n=6) was nutcracker esophagus. Group IV(n=7) was nonspecific esophageal motility disorder with low amp]itude contractions. We performed standard acid clearance test and compared it with the amplitude of esophageal contractions. Results: In Group I, the swal]owing number was 6.12+ 0.58(mean+ SE); in Group II, 15.33 3.96; and in Group lll and IV, 9.83 + 2.70 and 20.42 ' 4.43 respectively. The number of swallowing was significantly increased in Group IV than in the other groups(P=0.05) and showed the reversed correlation with amplitude(r=-0.81, p=0.026). Conclusions: Group IV had significantly delayed esophageal acid clearance and also showed the reversed correlation with amplitude. (Korean J Gastroenterol 1995;27: 493-498)