en Medical Obesity & Physiology Medical Obesity & Physiology Original Original <strong>Background and Objectives:</strong>&nbsp;To evaluate the association between menstrual cycle disorders with obesity in Iranian women.<br> <strong>Methods & Materials:</strong> In the present case-control study, 405 obese women of reproductive age who referred to the Obesity Clinic of Minimally Invasive Surgery Research Center, Rasoul-e-Akram Hospital, Tehran, between Jan 2013 and Oct 2015 were included as the case group and were compared with a control normal-weight group, selected from their family members (N=293). Menstrual cycle characteristics were documented in a researcher-designed checklist. For the statistical analysis, we used SPSS version 19 and Stata version 5.0.<br> <strong>Results: </strong>In the case group, 47 women (11.6%) had irregular menstrual cycles, while it existed in 22 (7.5%) of the control group (P<0.001). The prevalence of different menstrual disorders was as follows: polymenorrhea 107 (26.4%) in cases and 51 (17.4%) in controls (P<0.001), oligomenorrhea 22 (5.4%) in cases and 16 (5.5%) in controls (P<0.001).<br> <strong>Conclusion: </strong>The results of the present study showed that morbid obesity increases the risk of menstrual irregularities and dysmenorrhea; therefore, it is essential to pay greater attention to this issue in morbid obese patients for proper management of this disturbing comorbidity. Menstruation Disturbances, Obesity, Body Mass Index 31 36 http://annbsurg.iums.ac.ir/browse.php?a_code=A-10-78-1&slc_lang=en&sid=1 Zeinab Tamannaie zeinab_tamannaie@yahoo.com 10031947532846001938 10031947532846001938 No Shahid Beheshti University of Medical Sciences, Tehran, Iran Fatemeh Jesmi dr.jesmi@gmail.com 10031947532846001939 10031947532846001939 No Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran Meisam Akhlaghdoust meisam_akhlagh@yahoo.com 10031947532846001940 10031947532846001940 No Pars Advanced and Minimally Invasive Medical Manners Research Center, Pars Hospital, Iran University of Medical Sciences, Tehran, Iran Abdolreza Pazouki pazouki.a@iums.ac.ir 10031947532846001941 10031947532846001941 No Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran somayeh Mokhber dr_so_mo@yahoo.com 10031947532846001942 10031947532846001942 No Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran Shahla Chaichian shchaichian@gmail.com 10031947532846001943 10031947532846001943 Yes Pars Advanced and Minimally Invasive Medical Manners Research Center, Pars Hospital, Iran University of Medical Sciences, Tehran, Iran Mohadeseh Pishgahroudsari mo.pishgah@gmail.com 10031947532846001944 10031947532846001944 No Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran