Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 11 4 2020 04 06 156 165 Saeed Nemati Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, I.R. Iran. AND Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, I.R. Iran. Ali Rafei Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, I.R. Iran. Hedieh Mehrtash Center for Global Health, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America. Neal D. Freedman Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America. Akbar Fotouhi Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, I.R. Iran Kazem Zendehdel Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, I.R. Iran. AND Cancer Biology Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, I.R. Iran . 2020 01 07 2020 01 14 Background: To assess socio-economic inequality in the prevalence of tobacco smoking among Iranian adults in 2010. Methods: Data from the fifth national STEPS survey were analyzed. A blinder- Oaxaca decomposition model was applied to assess socio-economic inequality in the prevalence of daily cigarette and water-pipe smoking in men and women. Results: Overall, 4,203 participants appeared to be in the first and fifth quintiles of SES For men, the prevalence of daily cigarette smoking was higher among those with low SES  (23.1%) than those with high SES (11.1%) (P<0.001), which was mainly related to educational level (8.6%), residential area (-2.7%) and being exposed to cigarette smoker at home/work (1.3%). Likewise, we found a higher prevalence of daily water-pipe use among low SES (4.4%) women than high SES women (1.3%), Education plays a significant role in this difference (P=0.003). Conclusion: In conclusion, our findings reflect a strong association of education and economic level with tobacco smoking. Such factors must be considered as a pivotal basis for the design of tobacco control program at national and sub-national scales. https://bccr.tums.ac.ir/index.php/bccrj/article/view/331