Helicobacter pylori eradication therapy is recommended in the presence of H. pylori positive peptic ulcer disease and refractory iron deficiency anemia in adolescents among Japanese children. The eradication rate of the first-line triple therapy with a PPI+ amoxicillin+clarithromycin is falling to about 70%. A triple therapy with a PPI+ amoxicillin+metronidazole is acceptable as the second-line therapy. According to recent reports, the clarithromycin resistance rate is more than 40% in Japanese children. Antibiotics susceptibility testing before first-line therapies is taken into account. There is no available data about sequential therapy in Japanese children. The 13C-urea breath test and/or stool antigen test are recommended for confirmation of eradication at least 4 to 8 weeks following completion of therapy.