Background: Helicobacter pylori infection is known as an important risk factor in the development of ulcer, gastritis, and malignancy. However, recently, the systemic effect of H. pylori infection on other organs, such as infection of liver and development of non-alcoholic fatty liver disease, has been found. The prevalence of HPI in NAFLD patients has been noted, as the prevalence of NAFLD is growing worldwide. The aim of the present research was to determine the prevalence of H. pylori in NAFLD patients. Then, in case of positive relationship, through the easy and inexpensive control and treatment of H. pylori, it is possible to prevent development of NAFLD whose prevalence is increasing. Materials and methods: A descriptive cross sectional study was carried out. NAFLD patients referring to Digestion clinic of Loghman Hakin hospital were chosen using available sampling. After confirmation of NAFLD via ultrasound, serology test of H. pylori antibody (IgG) was requested. Then, the collected data were coded and introduced into computer. The quantitative data are described using mean and standard deviation, while the qualitative data are described by frequency and percentage. Chi2 and independent t-test were used for data analysis. The prevalence was determined by confidence interval %95, and the statistical tests were performed at significance level of %5. Results: In the present study, 181 NAFLD patients were tested. The mean age of the patients was 11. 95± 44. 15 years (male= %38. 7) 70); female= %61. 3) 111)). One patient (%0. 55) from the NAFLD group was Grade IV, 15 %8. 29)) were grade III, %28. 18) 51) Grade II, and most of the patients (%63, 114) were Grade I. H. pylori was positive among 114 patients (%63). The prevalence rates of positive IgG test among women and men were %64 and %61. 4, respectively. No significant difference was observed in IgG test prevalence between men and women (p=0. 731). No significance difference existed between the age of patients in terms of IgG test results, either (p=0. 441). Although the prevalence of H. pylori was less in non-smokers, no significant difference was observed in the prevalence of H. pylori in terms of smoking status. Finally, no significant difference was observed between the two groups in terms of BMI (p=0. 437). Conclusion: Our study indicated that the prevalence of H. pylori is relatively high in NAFLD patients. This high prevalence can be a cause for the possible relationship between H. pylori and NAFLD.