Sequential therapy (ST) which consists of standard dose PPIs + amoxycillin 2 g/D for 5 days with 5 additional days of clarithromycin 1g/D + metronidazole 800 mg/D has been proposed to increase an efficacy in HP eradication. A recent meta-analysis of over three thousand population revealed a higher eradication rate over PPI-based triple therapy (TT). A consistent finding from Thailand was reported an impressive success rate of ST in HP eradication up to 95%. Therefore, more updated guidelines recommend using ST, not TT, as the first line regimen. However, ST is a complicated regimen for the patients to be followed. This might cause a low adherence rate in clinical practice as well as development of drug resistance in near future.