Helicobacter pylori (H. pylori) infection is known as the most common cause of worldwide common chronic gastritis. Pathogenic mechanisms caused by H. pylori in diseases are still not fully understood. In addition, it has been reported that H. pylori can alter gene expressions in infected tissues and affect transcription factor activation. It is reported that aryl hydrocarbon receptor (AhR), which is a cytoplasmic transcription factor, functions in the immune system and plays a role in immune cells in barrier organs such as the gastrointestinal system, skin, and lungs. H. pylori infection affects the absorption of micronutrients such as trace elements, minerals, and vitamins by disrupting gastric secretion and acidification functions. Zinc (Zn) trace element is thought to be able to modulate the induction of AhR-responsive genes in endothelial cells. Although it is emphasized that trace elements are related with gastritis, relationship between Zn and AhR is not fully known, especially in chronic gastritis accompanied by H. pylori infection. In this study, serum levels of AhR, Zn, and AhR antagonist vitamin B12 were determined in chronic gastritis with H. pylori infection. Fifty volunteers diagnosed with H. pylori positive and negative chronic gastritis were included in this study. Collected from individuals participating were 5 ml of venous blood samples, and their serums were separated. AhR serum level of the study group was determined using enzyme-linked immunosorbent assay method. Zn concentrations in serum samples were measured using inductively coupled plasma atomic emission spectroscopy. When AhR and Zn serum levels were compared in H. pylori positive and negative chronic gastritis patients, it was found that AhR serum level of H. pylori positive chronic gastritis patients increased but it was not statistically significant (p = 0.595). However it was determined Zn and B12 serum levels were statistically significantly decreased (p < 0.001). This study has a crucial importance since to be the first one investigating relationship between serum AhR, Zn, and vitamin B12 levels in the pathogenesis of H. pylori gastritis in adults. Examination of AhR, Zn and B12 levels in H. pylori positive gastritis patients contributes to elucidating molecular mechanism of the disease.