Patients with diabetes are at increased risk of mortality and morbidity from micro- and macrovascular complications (1, 2). Landmark studies in type 1 and 2 diabetes have clearly shown that improved glycemic control leads to better outcomes (3-6). With the introduction of the General Medical Service contract, the England and Wales National Service Framework, and other schemes, there is a national drive to improve control in patients with diabetes. The treatment of diabetes was revolutionized shortly after the turn of the 20th century by the extraction and purification of insulin. Since methods to protract (i.e., prolong) the action of insulin were developed in the 1930s, little changed in this technology until the turn of this century. At this time there was renewed interest in the importance of basal insulin in controlling diabetes and thus preventing or delaying complications, and so technology advanced again. Two new basal insulin analogues have come to the market: insulin glargine, which has been widely used for some years now, and detemir. This review describes the novel method of protraction employed by insulin detemir, discusses the possible therapeutic benefits of this method of protraction, and describes the findings of studies comparing insulin detemir with other currently available basal insulin preparations. It is not the intention of this paper to be a review of all the currently available long-acting insulin analogues.