OBJECTIVES To investigate the possible correlation between infantile hypertrophic pyloric stenosis (IHPS) and Helicobacter pylori infection. MATERIALS AND METHODS In a case-control study, 20 infants with confirmed IHPS (Group 1) and 30 age-matched healthy infants (Group 2) were enrolled for the assessment of H. pylori infection. Serological testing of anti-H. pylori antibody (IgG) was performed preoperatively on all infants and their mothers. Also, H. pylori stool antigen test (HpSA) was carried out preoperatively on all infants in both groups. Statistical analyses were performed with Chi-square test, Fisher's exact test, Mann-Whitney U test, and Independent-Samples T test. RESULTS There were 20 patients in group 1 (18 boys, 2 girls) and 30 infants in group 2 (30 boys). The mean age in groups 1 and 2 were 42.40±18.09 days and 44.67±12.65 days, respectively. The numbers of positive HpSA and positive anti-H. pylori antibody both in infants and mothers were comparable between the two groups (P>0.05). The median titres of H. pylori stool antigen were not comparable between the two groups (0.20 ng/dL in group 1 vs 0.57 ng/dL in group 2; P=0.02). CONCLUSIONS H. pylori does not seem to be in a causative linkage with IHPS.