This study evaluated the association between Helicobacter pylori infection and height in a population of schoolchildren of a low socioeconomic level regarding growth-related micronutrient status. It was a cross-sectional study of 685 children 5-13 years of age. Height and weight were recorded, a (13)C urea breath test was performed for detection of H. pylori, and a blood sample was obtained for determination of micronutrient status. Helicobacter pylori infection was found to be associated with the height of children. Children with H. pylori infection are, on average, 1.32 cm lower (95% confidence interval [CI] = -2.22 to -0.42) in height than children without infection. There was an effect modification by age: for every one-year increase in age, height was 0.66 cm less (95% CI = -1.17 to -0.15) in children with H. pylori infection. This finding suggests that H. pylori infection has a negative effect on the growth of children.