Owing to the epidemics of type 2 diabetes, it is important to develop strategies of prevention of the disease. The first step should detect patients at risk, in function of simple anamnesis, clinical and biological criteria. Afterwards, those individuals should be encouraged to follow a prevention programme, which essentially comprises better lifestyle habits (diet and physical exercise), especially to prevent or correct weight excess. In at very high risk subjects, for instance because of moderately increased fasting or post-glucose load glucose levels, eventually in a context of family history of type 2 diabetes, a pharmacological approach could be considered. Various drugs (metformin, acarbose, glitazones, orlistat, inhibitors of the renin-angiotensin system) have proven their efficacy in reducing the incidence of type 2 diabetes, in particular in individuals with impaired glucose tolerance, with obesity and/or with arterial hypertension.