Fifty children aged 8-17 years with histologically confirmed chronic gastritis were investigated for Helicobacter pylori (H. pylori) presence in gastric mucosa bioptates taken during endoscopy. Three invasive tests (histology, rapid urease test and culture) were done. H. pylori was stated in 26 patients (56%). In this group the positive results were as follows: histology--96.4%, urease test--82.1%, culture--60.7%. The consistency of positive results ranged from 60.7% to 78.6%, being most often for histology and urease test. In 91% of non-infected patients the endoscopic features were limited to erythematous, oedematous and exsudative changes of gastric mucosa, whereas in patients with H. pylori infection the prevalence of antral nodularity was noted in 60.7%. The probable causes of non compatible test results are discussed.