Insulin detemir is a novel long-acting insulin analogue with a unique mechanism causing prolonged duration of action. This is because of its self-association into hexamers and dihexamers and to bind reversibly to albumin. Insulin detemir remains soluble after it is injected. Clinical studies showed insulin detemir administered once or twice daily is as effective as NPH insulin and insulin glargine in achieving glycaemic control. Most trials shown that insulin detemir exhibits less intra-patient variability in glycaemic control compared with NPH insulin and insulin glargine. One of the benefits of insulin detemir is its favorable effect on bodyweight. In addition, a reduced risk of nocturnal hypoglycaemia has been reported with insulin detemir compared with NPH insulin in patients with diabetes. These data indicate that insulin detemir is a valuable option for basal insulin therapy in patients with type 1 or type 2 diabetes.