Background: Helicobacter pylori (H. pylori) is the most common chronic infectious agent in the stomach.Most importantly, it may lead to atrophy, metaplasia and cancer. The aim of this study was to investigate theincidence of H. pylori infection and to detect early mucosal changes that may lead to malignant degenerationin children. Materials and Methods: Children who underwent upper gastrointestinal endoscopy were included.Familial history of gastric cancer was noted. Endoscopic examinations were performed by a single pediatricgastroenterologist. A minimum of three biopsy samples were collected during endoscopy. The patients wereaccepted as H. pylori infected if results of biopsies and rapid urease test were both positive. Biopsies wereevaluated for the presence and degree of chronic inflammation, the activity and severity of gastritis, glandularatrophy and intestinal metaplasia. Results: A total of 750 children (388 boys, 362 girls) were evaluated in ourstudy, with a mean age of 10.1 years. A total of 390 patients (52%) were found to be infected with H. pylori.Among the H. pylori infected patients, 289 (74%) were diagnosed to have chronic superficial gastritis, 24 (6.2%)had gastric atrophy. Most strikingly, intestinal metaplasia was observed in 11 children, all were in the H. pyloripositive group. There was no difference in the mean of age, gender and socioeconomic class between H. pyloriinfected and non-infected groups. The frequency of gastric cancer in family members (4 in number) was higherin patients with H. pylori infection. No gastric cancer case was reported from the parents of non-infected children.The worst biopsy parameters (atropy and metaplasia) were improved after H. pylori eradication on controlendoscopy. Conclusions: The current study shows a higher prevalence of familial history of gastric cancer in H.pylori infected children. Intestinal metaplasia was also higher in the infected children. Eradication of H. pyloriinfection for this risk group may prevent subsequent development of gastric cancer.