objectives ？ to determinate prevalence of helicobacter pylori infection in a group of symptomatic patients between 2 and 18 years old who were submitted to gastric biopsy during upper endoscopy done in the period of 1990-97. to correlate the histological findings with clinical and endoscopical data. methods ？ a cross-sectional study done after review of clinical and histopathological data. histopathological sections were reviewed by a pathologist, who did not know the clinical information and the previous histopathological reports. results ？ among 181 patients evaluated, prevalence of helicobacter pylori infection was 24.86% (45 positive cases). in pathological analysis, gastritis was found in 38/45 of the positive helicobacter pylori patients and in 45/136 negative helicobacter pylori. gastric ulceration was found in 6/45 positive helicobacter pylori and in 3/136 negative helicobacter pylori. conclusion ？ this study stated a significative association between helicobacter pylori infection and pathological abnormalities in children evaluated in the "hospital de clínicas de porto alegre", rs, brazil.