The effect of Helicobacter pylori infection on the nutritional status of children in a developing country was studied using a cross-sectional design. Children attending an all-girl public school in inner Guatemala City, Guatemala were evaluated to acquire sociodemographic information and anthropometric nutritional parameters (weight-for-height [WFH] and height-for-age [HFA]), and detect H. pylori-specific serum IgG antibodies. Of 211 children 5-10 years of age, 107 (51%) were infected. The WFH values were not different between infected and uninfected subjects, and were not affected by the sociodemographic variables. The HFA values decreased significantly with age (P = 0.008), lower income (P = 0.04), and H. pylori infection (P = 0.05). When controlled for age and income level, the effect of infection on HFA became nonsignificant (P = 0.30). Helicobacter pylori appeared to have no effect on the nutritional status of the studied children; the differences detected were small and likely due to sociodemographic factors.