Fasting during holy month of Ramadhan is an obligatory for all healthy adults Muslims. When making decision of fasting it is important to consider both religious and health aspects. From medical point of view, patients with type- 1 diabetes are generally advised strongly to not fast. Many risks and complications including hypoglycemia, hyperglycemia, ketoacidosis, dehydration are associated in both type one and type two diabetes with fasting. Patients should not stop taking medications during Ramadhan; however, they should go through assessment and education about diet plan and drugs before the beginning of Ramadhan in order to get right adjustment to the types and dosage of their medications.