Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects the gastrointestinal mucosa. H. pylori causes serious gastrointestinal diseases such as chronic gastritis, peptic ulcers, gastric lymphoma and gastric adenocarcinoma, which can be eliminated by treating the infection. Various diagnostic methods have been proposed in children, which are divided into invasive and non-invasive. Non-invasive tests have been the most common diagnostic methods for H. pylori in children, although their accuracy is not very accurate in some cases. UBT, SAT and serology are types of non-invasive diagnostic methods in children that are performed on samples obtained from patients' blood and feces. Invasive procedures are performed on specimens obtained from patients' gastric biopsies and require upper gastrointestinal endoscopy. Among aggressive methods, RUT is preferred because of its fast results, easy availability, lower cost, and high sensitivity and specificity.