PURPOSE: Non-bismuth concomitant quadruple therapy is commonly administered in Taiwan, achieving an acceptable efficacy as a first-line anti-Helicobacter pylori treatment. This study compared the eradication rates between esomeprazole- and lansoprazole-based non-bismuth concomitant quadruple therapy for first-line anti-H. pylori treatment. PATIENTS AND METHODS: This study included 206 H. pylori-infected naïve patients between July 2016 and February 2019. The patients were prescribed with either a 7-day non-bismuth containing quadruple therapy (esomeprazole, 40 mg twice daily; amoxicillin, 1 g twice daily; and metronidazole, 500 mg twice daily; and clarithromycin, 500 mg twice daily for 7 days [EACM group]; lansoprazole, 30 mg twice daily; amoxicillin, 1 g twice daily; metronidazole, 500 mg twice daily; and clarithromycin, 500 mg twice daily [LACM group]). Then, the patients were asked to perform urea breath tests 8 weeks later. RESULTS: The eradication rates in the EACM group were 86.1% (95% confidence interval [CI], 77.8%-92.2%) and 90.6% (95% CI, 82.9%-95.6%) in the intention-to-treat (ITT) and the per-protocol (PP) analyses, respectively. Moreover, the eradication rates in the LACM group were 90.1% (95% CI, 82.6%-95.2%) and 92.6% (95% CI, 85.5%-96.9%) in the ITT and the PP analyses, respectively. Consequently, the LACM group exhibited more diarrhea patients than the EACM group (7.1% versus 1.0%, p = 0.029), but all symptoms were mild. Univariate analysis in this study showed that metronidazole-resistant strains were the clinical factor affecting the eradications (95.3% versus 78.9%, p = 0.044). Moreover, a trend was observed in dual clarithromycin- and metronidazole-resistant strains (91.5% versus 66.7%, p = 0.155). CONCLUSION: The eradication rates between esomeprazole and lansoprazole-based non-bismuth concomitant quadruple therapy for first-line H. pylori treatment were similar in this study. Both could achieve a > 90% report card in the PP analysis.