Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 52 8 2023 08 06 1600 1612 Soheil Hassanipour Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran Ehsan Amini-Salehi Student Research Committee, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran Farahnaz Joukar 1. Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran 2. Caspian Digestive Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran Mohammad-Javad Khosousi Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran Farideh Pourtaghi Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Malek Moein Ansar Department of Biochemistry, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran Marjan Mahdavi-Roshan Cardiovascular Diseases Research Center, Department of Cardiology, Heshmat Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran Forough Heidarzad Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran Golnaz Rashidi-Mojdehi Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran Elham Abdzadeh Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran Azin Vakilpour School of Medicine, Guilan University of Medical Sciences, Rasht, Iran Fariborz Mansour-Ghanaei 1. Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran 2. Caspian Digestive Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran 2022 05 16 2022 12 28 Background: Non-alcoholic fatty liver disease (NAFLD) is the world's most common etiology of chronic liver disease. In this systematic review and meta-analysis, we estimated the prevalence of NAFLD in the Iranian children and adult population. Methods: A comprehensive search of five international databases, including PubMed, ISI/WOS, ProQuest, Scopus, and Google Scholar, was done from inception to Nov 2022. Studies on NAFLD patients and their risk factors were selected for meta-analysis. The quality of the included studies was assessed by The Joanna Briggs Institute (JBI) Critical Appraisal Checklist for cross-sectional, and cohort studies. The heterogeneity between studies was investigated using Cochran test and I2 statistics. Random and fixed effect models were used for heterogenic and non-heterogenic studies, respectively. We used Comprehensive Meta-Analysis version 3 for conducting meta-analysis. Results: Twenty studies were finally included. The total prevalence of NAFLD in children, boys, and girls was 6.7% (95% CI: 0.02-0.18), 12.5% (95% CI: 0.04-0.29) and, 10.1% (95% CI: 0.04-0.21), respectively. The total prevalence of NAFLD in obese children, obese boys, and obese girls was 42% (95% CI: 0.18-0.69), 44% (95% CI: 0.13-0.80), and 33 % (95% CI: 0.13-0.62), respectively. The total prevalence of NAFLD in adults was 36.9% (95% CI: 0.31-0.42). The prevalence of NAFLD in men and women was 33.8% (95% CI: 0.27-0.41) and 29.9% (95% CI: 0.21-0.40), respectively. Conclusion: NAFLD prevalence in Iranian adults and obese children is considerable; however, data about the children population was insufficient. https://ijph.tums.ac.ir/index.php/ijph/article/view/28764 https://ijph.tums.ac.ir/index.php/ijph/article/download/28764/8004