Background: H. pylori infection is strongly related with chronic gastritis of the antrum of the stomach, which causes impairment in gastric acid and pepsin secretion, and is thus linked to malabsorption of food-vitamin B12. H. pylori can cause an individual to have a vitamin B12 deficiency. It is also a known contributor to gastritis ulcers and it can prevent the stomach from being able to absorb the vitamin B12 you consume and leads to a deficiency of vitamin B12. The purpose of this study is to determine the frequency of vitamin B12 deficiency in Helicobacter pylori infected patients. Methods: All patients aged 17 - 65 years, of either gender were evaluated for urine vitamin B12 level by human vitamin B12 ElSA kit. The data were analyzed in statistical software (SPSS) and the P-value = 0.05 was considered as statistically significant. Results: Of one hundred subjects, 65 (65%) were males, while 35 (35%) were females. 31 (36.0%) H. pylori infected patients had normal vitamin B12 level and 55 (64%) were Vitamin B12 deficiency in 86 (86%). H. pylori infected patients with a significant difference (P value < 0.05). Conclusions: Vitamin B12 deficiency is more prevalent in Helicobacter pylori infected patients.