The focus of this review is inhaled insulin, specifically Exubera, which represents a novel prandial insulin delivery method. Fear of hypoglycaemia and the reluctance of patients to use multiple daily injection regimens is a major barrier to achieving good glycaemic control in patients with type 1 and type 2 diabetes. Inhaled insulin has been developed to provide more physiological prandial insulin replacement than regular human insulin in patients with diabetes, with the advantage of non-invasive delivery. Good glycaemic control, comparable to modern subcutaneously administered insulin preparations, has already been demonstrated, and no unexpected safety concerns have been reported with inhaled insulin. The development of such insulin delivery technologies that are better tailored to patients' needs may improve patient compliance, thereby facilitating the attainment of treatment targets. This review summarises the studies available and discusses the potential implications to patients of needle-free insulin administration.