Background and Objectives: Gastric cancer is the second most common cause of cancer in terms of mortality in the world. Ardabil province, in northwestern Iran, has the highest rate of gastric (predominantly cardia) Adeno carcinoma in Iran. The most common site of upper gastrointestinal cancer in Ardabil is cardia region (its right-side wall). Therefore this study aimed to investigate comparatively histopathology of right and left side of cardia and z-line considering the incidence of inflammatory and precancerous lesions.

 Methods: This descriptive and cross-sectional study was performed on one hundred adults who referred to Aras clinic for endoscopy. Endoscopy was done with video endoscope and a single biopsy was taken from right and left side of cardia and z-line respectively and one from antrum for H.Pylori. All the samples of the biopsy material were fixed in formalin in separate bottles and pathologic study of the samples with regard to inflammatory and precancerous lesions were done according to Sydney classification of gastritis. The collected data were�analyzed by SPSS software using descriptive and analytical statistics.

 Results: 61 (61%) patients were male and 39 (39%) female. The age range of patients was 19-80 years old (standard deviation 53±16.2). Mild to severe inflammation in left and right side of cardia and z-line was 82.6%, 84%, 97.1%, 93%, mild to severe atrophy in 22.8%, 28.7%, 26.5%, 24.4% and metaplasia type 1 to 3 in 2.2%, 6.4%, 2.9%, 12.2% respectively. Suspected dysplasia in cardia and z-line was only in one case. Analysis of these variables with McNamara, Wilcoxon and Lambda tests showed no statistically meaningful difference considering the histopathological findings in left and right side wall of cardia and z-line

 Conclusion: This study showed no statistically meaningful difference between right and left wall of cardia and z-line considering the incidence of inflammatory and precancerous lesions. This observation is not consistent with high incidence of right sided cardia cancer. Further study with multiple biopsy sample and more sensitive methods is recommended for the diagnosis of precancerous lesions.