No nation is exempt from the concern of the so-called “diabetes epidemic.” Diabetes is associated with a multitude of short-term and long-term complications, and, hence, a clinical diagnosis of diabetes mellitus is a costly occurrence in terms of health care resource utilization and adverse health outcomes.2 In the U.S. in 2002, the direct medical costs for treating diabetes and its complications were calculated to be $92 billion. Indirect costs, resulting from lost workdays, limited activity, and lifelong disability, adds to this economic burden by another$40 billion. Blindness, chronic renal failure, and lower limb amputation are the feared sequelae of diabetes. Emergency physicians face diabetes under several circumstances: they may be called on to evaluate and treat the acute or chronic complications of diabetes or of its treatment [such as diabetic ketoacidosis (DKA), foot ulcer, or hypoglycemia], or they may in some cases diagnose diabetes in a patient for the first time. Moreover, a diabetic patient may be admitted to the ED for a condition not directly related to diabetes and requires consideration of his/her special needs. For these reasons, a basic knowledge of diabetes is essential for every practicing emergency physician.