Background/Aims: To evaluate and compare the efficacy of QuickVue H. pylori test and IgG ELISA test in diagnosis of Helicobacter pylori infection. Methods: One hundred patients(46 gastritis patients, 18 gastric ulcer patients, 18 duodenal ulcer patients, 15 nonulcer dyspepsia patients, 3 others including gastric cancer and adenoma) were enrolled in this study. Endoscopic gastric antral biopsy specimens were obtained for microscopic examination of the bacteria and rapid urease test(CLO test). Bio-Rad GAP IgG ELISA test(Bio-Rad Chemical Division, U.S.A.) and QuickVue H. pylori test(Quidel, U.S.A.) were also performed for serologic diagnosis of H. pylori infection. Detection of H. pylori by microscopy was considered as true positive for H. pylori infection. Absence of H. pylori by microscopy and positive CLO test was considered as equivocal and these cases were exc]uded in the analysis of the data. Results: 57 patients(57%) were positive, 36 patients(36%) were negative and 7 patients(7%) were equivocal in H. pylori infection. The sensitivity of IgG ELISA test was 84.2% and the specificity was 52.8%. The sensitivity of QuickVue H. pylori test was 87.7% and the specificity was 61.1%. Conclusions: Both serologic tests for the diagnosis of H. pylori infection are comparable in sensitivity and specificity.(Korean J Gastroenterol 1997; 29:35 -40)