The main changes of the first revision of the guideline of the Dutch College of General Practitioners on the diagnosis and treatment of diabetes mellitus type 2 compared with the first edition concern the following aspects: more attention is given to organisation and management of diabetes care; new diagnostic criteria for diabetes are introduced; guidelines are given for the early detection of diabetes in high risk groups; the distinction between sulfonylureas of the first and the second generation has been dropped; in the treatment of patients with diabetes and a body mass index > 27 metformin is the drug of first choice; optional guidelines are given for the treatment with insulin; guidelines are given for the treatment of hypertension and hypercholesterolaemia in patients with diabetes.