Gastritis can be defined in the simplest way such as inflammation of gastric mucous membrane. There are numerous causes of gastritis and the most often is Helicobacter pylori infection. Studying of the blood groups also includes the question of their connection with certain diseases. Up to date it has been explained the role that blood groups have in haemolytic disease of newborn infant but for other diseases we know little, it is insufficient or we know nothing. The aim of this work was to analyze connection of chronic gastritis in childhood, Helicobacter pylori and ABO blood groups. It has been treated 68 patients out of which 57 (83%) were Helicobacter pylori positive (Hp+) and 11 (17%) were Helicobacter pylori negative (Hp-). Thirty patients had chronic gastritis out of which 22 (73%) were Hp+ and 8 (27%) Hp-. It prevailed blood group A and O, comparing with other blood group phenotypes connected with gastritis.