Diabetes is one of the most common endocrine abnormalities in childhood. There are three main types of diabetes affecting children: type 1 diabetes, type 2 diabetes, and maturity onset diabetes. Control of diabetes in the young usually requires management with subcutaneous insulin injections. There are many different types of insulin regimens in use, each tailored to the individual needs of the child. Children undergoing surgery have a metabolic response to the surgery and anaesthesia. This neuroendocrine stress response results in an increase in catecholamines and cortisol with a decrease in insulin secretion from the pancreas. In addition to investigations required for the proposed surgery, all diabetic children should have their blood glucose, urea, creatinine and electrolytes measured and these should be within the normal range. Prolonged periods of fasting must be avoided and the diabetic child should be scheduled either first or early on the operating list.