A fast development in therapy with insulin was observed after its discovery. Besides the widely used human regular insulin preparations, nowadays ultrashort and long-acting insulin analogues are also available for the patients. At present, the results of large clinical trials enable an evidence based diabetes care. It is well documented, that near-normoglycemia should be achieved by intensive conservative insulin treatment or pump therapy in type 1 diabetic patients. The beneficial effects of the good metabolic control could also be observed years later concerning late specific complications of diabetes. Similarly, as good as possible metabolic control should be aimed with antidiabetic treatment including insulin, if necessary, in type 2 diabetic patients. It is documented that the risk of cardiovascular complications is not increased in type 2 diabetic patients treated with insulin. Hypoglycemia and weight gain are the most important side effects of the insulin treatment. Recently, evidence based recommendations for treatment with ultrashort (insulin lispro, insulin aspart) and long-acting insulin analogues (glargine) can also be determined.