Consistent antihyperglycaemic treatment for preventing vascular complications in type 2 diabetes mellitus (2DM) often require the application of several measures. The basis of such treatment should be dietary changes and increased physical exercise. The target of antiglycemic treatment is the reduction of HbA1c to below 6.5%. Regular monitoring of HbA1c every 2-6 months is reasonable in order to recognize therapeutic failure early and adapt treatment accordingly. Metformin is the drug of first choice for the oral treatment of 2DM, once possible contraindications having been excluded. The advantage of glinides, compared with sulfonylureas, is mainly in allowing greater dietary flexibility. Although not finally decided, there are ever fewer objections against combined metformin and sulphonylurea treatment. The current guidelines of the (British)National Institute for Clinical Excellence (NICE) specifically recommend this combination treatment. There are pointers to glitazone having protective effects in 2DM beyond its blood-sugar lowering action. However, the clinical significance of these effects requires confirmation. If adequate blood-sugar reduction cannot be achieved with oral medication it is important to initiate insulin administration as soon as possible.