Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 53 10 2015 10 27 596 607 EN Asghar Rahmani Student Research Committee, Ilam university of Medical Sciences, Ilam, Iran. Kourosh Sayehmiri Psychosocial Injuries Research Center, Ilam university of Medical Sciences, Ilam, Iran. AND Social Medicine Department, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran. Khairollah Asadollahi Psychosocial Injuries Research Center, Ilam university of Medical Sciences, Ilam, Iran. AND Social Medicine Department, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran. Diana Sarokhani Student Research Committee, Ilam university of Medical Sciences, Ilam, Iran. Farhad Islami The Tisch Cancer Institute, Institute for Transitional Epidemiology, Mount Sinai School of Medicine, New York, United States. AND Digestive Disease Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Mandana Sarokhani Psychosocial Injuries Research Center, Ilam university of Medical Sciences, Ilam, Iran. 2015 10 26 Obesity is one of the main public health problems which underlie many chronic illnesses and socioeconomic difficulties. According to the literature review, there are limited data on the prevalence of obesity in different parts of Iran as well as its trend and prevalence among different age and gender groups. The aim of this study was to estimate the obesity prevalence in Iran using meta-analysis. All the corresponding articles published in the external and internal journals, final reports of research projects, articles of related congresses and the reference index of the correlated papers published between 1995 and 2010 were collected via the electronic research engines (PubMed, Scopus, SID, Magiran, IranMedex).  Data were analyzed using meta-analysis (random effects model) and meta-regression). A total of 144 articles with the sample size of 377858 people (134588 males and 164858 females) were enrolled in the study. The prevalence of obesity in populations above the age of 18 was estimated as 21.7% (CI 95%: 18.5% - 25%) and in populations below 18 as 6.1% (CI 95%: 6.8%-5.4%). Meta-regression analysis showed an ascending trend in the prevalence of obesity in Iran. The prevalence rates of obesity according to the BMI index, NCHC and percentile above 95 were 17.4%, 7.6% and7.4%, respectively. The BMI mean was 19.3 in populations below the age of 18 (CI 95%: 17-21.6) and 25.2 in those above the age of 18 (CI 95%: 27.1-23.3). Considering the increasing rate of obesity in Iran and its effects on the public health, corresponding health authorities should revise the obesity preventive programs and, using public health interventions, reduce the rate of obesity in the country. https://acta.tums.ac.ir/index.php/acta/article/view/5069 https://acta.tums.ac.ir/index.php/acta/article/download/5069/4696