Nan-Chang Chiu,1,2,* Chien-Yu Lin,3,* Hsin Chi,1 Chun-Yan Yeung,1,2 Wei-Hsin Ting,1 Wai-Tao Chan,1 Chuen-Bin Jiang,1 Sung-Tse Li,3,4 Chao-Hsu Lin,3 Hung-Chang Lee1,2 1Department of Pediatrics, MacKay Children’s Hospital, 2Department of Medicine, MacKay Junior College of Medicine, Nursing and Management, Taipei, 3Department of Pediatrics, Hsinchu MacKay Memorial Hospital, Hsinchu City, 4Department of Statistics and Information Science, Fu Jen Catholic University, New Taipei, Taiwan *These authors contributed equally to this work Purpose: The long-term impact of Helicobacter pylori infection is complex, and concerns about the need for eradication exist. We conducted this case control study to investigate the association between H. pylori infection and failure to thrive (FTT).Patients and methods: From January 2009 to December 2011, 53 children with FTT group and matched children with the same sex and age and similar socioeconomic status without FTT (control group) were enrolled. A questionnaire was administered to the parents/guardian, and a 13C-urea breath test was performed to detect H. pylori infection.Results: We found that the total prevalence of H. pylori infection was 29.2% and that there was no association between FTT and H. pylori infection (FTT group: 32%; control group: 26.4%; P=0.67). Short stature was more common in the FTT group and abdominal pain in the control group (FTT group: 37.7%; control group: 11.3%; P=0.003). In a comparison between the H. pylori-positive and -negative groups, abdominal pain (87.1% vs 64%; P=0.032) and the frequency of endoscopy (74.2% vs 32%; P<0.001) were significantly more common in the H. pylori-positive group.Conclusion: We found that children with H. pylori infection are at an increased risk for abdominal pain and that FTT is not associated with H. pylori infection. The decision for eradication should be evaluated carefully and individualized. Keywords: Helicobacter pylori, 13C-urea breath test, failure to thrive, growth retardation, children