The pulmonary route, due to its rich vascularity, large surface area and immunotolerant characteristics, may be an ideal target for drug delivery. Although the inhaled route has been used to deliver drugs used in the management of respiratory disorders, success with peptide delivery has been limited by poor bioavailability. Recent advances in technology have overcome these barriers and have enabled new delivery devices to be developed. Insulin is the first peptide to be delivered successfully by this route and the first of the inhaled insulin delivery devices (Exubera) has now been approved for clinical use. In clinical trials it has been shown to be effective, apparently safe and a preferred alternative to subcutaneously injected meal-time insulin. This new technology offers great convenience to patients needing insulin treatment. While it will considerably reduce the number of injections needed by people with type 1 and type 2 diabetes, it should also encourage more patients to start insulin treatment earlier. The potential benefits from improved adherence and better glycaemic control with this insulin are also significant.