The objective of the study is to investigate the value of serum iron index in patients infected with Helicobacter pylori and find out the correlation between serum iron index and sociodemographic characteristics in patients infected with Helicobacter pylori at faculty 2 of University Medical Center Ho Chi Minh City. The study used CLO and HP CIM tests to determine the Helicobacter pylori infection status, and also collected the serum/plasma of the patient after the HP CIM test to investigate the serum iron index. The Stata 14.0 software was used to manage and analyse data, the ANOVA test was used to test for 3 means or more, and the Chi-squared test wasused to test the difference in proportions between groups. The results showed that the serum iron concentration in the patient group was 59,4±42,1 mg/dL lower than the serum iron value in the control group, which was 86,1±32,0 mg/dL (p < 0,001). The results also indicated that the serum iron value in patients infected with Helicobacter pylori decreased as compared to patients without infection, yet the study also found a relationship between age group and geographical factors. This difference is statistically significant with p <0,001, p = 0,001, p = 0,04 and p = 0,001.