en Epidemiology Epidemiology Original Research Original Research <p> <strong> Background: </strong>Health literacy is the ability to obtain, read, understand and use healthcare information to make appropriate health decisions and follow instructions for treatment. The aim of this study was to identify the effect of various factors on health literacy in patients with diabetes. </p><p> <strong> Methods: </strong>This was a cross-sectional observational study of 407 Iranian patients older than 15 years of age with type 1 and 2 diabetes identified from the Diabetes Clinic affiliated to the Institute of Endocrinology and Metabolism (IEM) of Iran University of Medical Sciences. We assessed patients' health literacy using the Persian version of Test of Functional Health Literacy in Adults (TOFHLA) questionnaire. </p><p> <strong> Results: </strong>The mean age of the patients was 55.85 years, and 251 (61.7%) of them were female. Females had lower educational level compared to males (p< 0.001). In total, 18.2%, 11.8% and 70.0% of the participants had adequate, marginal and inadequate health literacy scores, respectively. Tukey’s post hoc test revealed that employed patients enjoyed  a high health literacy level compared to housekeepers (p< 0.001). </p><p> <strong> Conclusion: </strong>Health literacy score in Iranian patients with diabetes seems low. Therefrom effective interventions should be designed and implemented for this group of patients to improve diabetes outcomes. </p> Health literacy, Diabetic patients, Influencing Factors. 566 571 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-854&slc_lang=en&sid=1 Zahra Mohammadi mimina_13@yahoo.com 200319475328460018162 200319475328460018162 No Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran. Arash Tehrani Banihashemi tehranib@gmail.com 200319475328460018163 200319475328460018163 Yes Department of Epidemiology, School of Public Health, Iran University of Medical Sciences & Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran. Homa Asgharifard asgharifard@razi.tums.ac.ir 200319475328460018164 200319475328460018164 No Dezful University of Medical Sciences, Khuzestan, Iran. Mehran Bahramian dr_mehran_b@yahoo.com 200319475328460018165 200319475328460018165 No Faculty of Medicine, Emergency Department, Alborz University of Medical Sciences, Karaj, Iran. Hamid Reza Baradaran baradaran.hr@iums.ac.ir 200319475328460018166 200319475328460018166 No Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran. Mohammad E Khamseh mekhamseh@gmail.com 200319475328460018167 200319475328460018167 No Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran.