The role of Helicobacter pylori infection (HPI) in the development of chronic gastritis, ulcer disease, MALT-lymphoma, stomach cancer, and other diseases is considered. HPI is directly or indirectluy associated with colon adenoma and colorectal cancer, hepatic disorders, coronary heart disease, idiopathic iron deficiency anemia and thrombocytopenia. The role of HPI in the development of gastroesophageal reflux disease remains to be elucidated. HPI is negatively related to bronchial asthma and chronic inflammatory intestinal diseases. Pathophysiological and clinical aspects of HPI and the aforementioned pathologies await further investigations.