Background: Blood group carbohydrates are proposed to influence the risk of acquiring Helicobacter pylori (H. pylori) by effects on adhesion to the gastric mucosa. The objective of this study was to evaluate the association between ABO blood groups and H. pylori infection in adults. Materials and methods: Cross sectional study was carried out on 300 individuals at Al Shomali general hospital, Babylon, Iraq. ABO and Rhesus (Rh) blood groups were determined for all participants by standardized hemagglutination methods. Detection of H. pylori IgG antibodies in blood serum was performed by rapid strip test specific to H. pylori. Results: The current study included 300 persons. They were divided in to two groups; H. pylori positive group 174 (58%) and H. pylori negative group 126 (42%). Blood group O considered as a risk factor associated with H. pylori infections; the odds ratio (OR) was 2.15 (95 CI: 1.29- 3.58; p < /em>= 0.003). Blood group B considered as a risk factor associated with H. pylori infections the OR was 1.84 (95 CI: 1.09- 3.11; p < /em>= 0.029). Blood type AB was predominant in only 10 (5.74%) of 174 of positive group. Whereas it was 40 (31.74%) of 126 of negative group; the OR was 0.13 (95 CI: 0.06- 0.27; p < /em>< 0.001). Conclusion: Blood group O and B are considered as a risk factor associated with H. pylori infections.Blood group AB is considered as a protective factor against H. pylori infections. Blood type A has no effect