The practice guideline 'Diabetes mellitus type 2' (second revision) addresses the diagnosis, treatment and management of adults with diabetes mellitus type 2 in general practice. The aim of management is the prevention and treatment of diabetes-related symptoms and complications such as cardiovascular disease, nephro-, retino- and neuropathy. The general practitioner gives the patient education and lifestyle advice and repeats this regularly. In addition, the general practitioner and the patient strive to achieve good glycaemic control. The agent of first choice in the medicinal treatment of all type 2 diabetic patients is metformin. This is continued even after the addition of a sulphonylurea derivative or insulin. This represents a change compared to the previous version of the practice guideline. The indications for thiazolidinediones are limited. To reduce the cardiovascular risk, it is advised to aim at a systolic blood pressure below 140 mmHg. It is also recommended that each patient be prescribed a statin, unless the patient belongs to a subgroup in which the indication for cholesterol lowering therapy is weak or the patient refuses it. Compared to the former guideline, more emphasis is placed on the prevention of nephropathy. The general practitioner is advised to calculate the creatinine clearance yearly and to test for relevant albuminuria in each patient with a life expectancy of 10 years or more. If microalbuminuria is present, the patient is prescribed an angiotensin converting enzyme (ACE) inhibitor, even if the blood pressure is not elevated. The detection of patients with a high risk of diabetic ulcer is also given more emphasis.