Background/Aims: Ecabet sodium is known for its bactericidal effect against H. pylori. It was reported that a supplement of ecabet sodium to conventional triple therapy showed good results in Asia. The Aim of this study was to ascertain the efficacy of additional ecabet sodium on conventional triple therapy for eradication of H. pylori. Methods: We reviewed the cases of 111 patients (Group A) with H. pylori infection who received ecabet sodium with triple therapy (20 mg of rabeprazole, 1 g of amoxicillin, 500 mg of clarithromycin and 1 g of ecabet sodium, twice daily for 7 days). Another 186 patients (Group B) received PPI-based triple therapy (same as the above, except without the ecabet sodium). Eradication was evaluated 4 weeks later after completion of treatment by 13C-UBT. Results: Eradication rates were 74.8% (83/111) in group A and 70.4% (131/186) in group B by intention-to-treat analysis (p=0.420), and 75.2% (82/109) in group A and 70.7% (128/181) in group B by per protocol analysis (p=0.405). Conclusions: The addition of ecabet sodium to conventional triple therapy did not increase the eradication rate of H. pylori in this study. These findings imply that ecabet sodium as an additional agent cannot overcome antibiotic resistance, which is the most important cause of failure of triple therapy.