Independently of its initial mechanism, Type 2 diabetes associates in various degrees disorders in insulin sensibility and secretion. The dissociated insulin resistance among tissues explains the predictable imperfection of insulin therapy in this disease due to frequent weight increase and the potential risks of insulin on atherogenesis raised on the basis of experimental studies. All diabetic subjects are not equally insulin resistant and do not have the same insulin secretory capacity evaluated in practice by means of the response of insulin or C peptide plasma levels to various secreting agents. Intensity and duration of hyperglycaemia, muscular mass, physical activity and way of life, age, weight and fat patterning, the presence of complications, acceptance, education feasibility and compliance are essential in selecting towards insulin therapy. Meanwhile, as the results of the prospective studies in progress become available, it seems that insulin should be restricted to the smallest useful dosage possible and that weight change should be carefully checked within the weeks following initiation of insulin. The future of insulin therapy in Type 2 diabetes requires (1) better selection of patients showing a demonstrated beneficial effect of insulin, (2) the association of insulin with new molecules capable of reducing its dosage and preventing its deleterious effects, (3) a change in the mode of insulin administration, with an appropriate balance between comfort and efficacy, (4) change in the insulin structure towards analogues or compounds related to insulin but with less perverted effects.