Considering the fact that many Muslims with diabetes prefer to fast in spite of inhibitory advises and to answer several conflicts and controversies regarding diabetes and Ramadan, IDF in collaboration with Diabetes and Ramadan (DAR) International in Alliance decided to develop a comprehensive guideline to be used by health care professionals. This guideline was then developed on April 2016 by 12 main authors and 20 co-authors from all around the world, and published by International Diabetes Federation. The guideline is provided in nine chapters: 1) Introduction to the IDF-DAR Practical Guidelines, 2) Epidemiology of Diabetes and Ramadan Fasting, 3) Physiology of Ramadan Fasting, 4) Risk Stratification of Individuals with Diabetes before Ramadan, 5) Diabetes and Ramadan: A Medico-religious Perspective, 6) Pre-Ramadan Education, 7) Ramadan Nutrition Plan (RNP) for Patients with Diabetes, 8) Management of Diabetes during Ramadan and 9) Identifying and Overcoming Barriers to Guideline Implementation. This guideline tries to answer three main questions: 1) Is fasting during Ramadan associated with a significant risk? 2) What are the criteria that predispose patients with diabetes to increased risk during fasting? 3) What is the most appropriate oral anti-diabetic drug(s) or type and regimen of insulin for patients with type 2 diabetes who fast? IDF-DAR Practical Guideline is now available at: http://www.idf.org/sites/default/files/IDF-DAR-Practical-Guidelines-Final-Low.pdf