The numbers of people with type 2 diabetes are rising rapidly around the world, making it imperative to develop and introduce methods of preventing the condition. A series of clinical trials over the last decade has shown conclusively that lifestyle interventions focusing on physical activity, diet, and weight loss can reduce the risk of developing type 2 diabetes by approximately 60%. Trials examining pharmaceutical interventions have shown that metformin, acarbose, and glitazones also reduce the risk of developing diabetes, but have shown no benefit of ACE inhibitors. Although uncertainty remains about the widespread use of pharmaceutical agents for diabetes prevention, programmes to implement lifestyle changes in those at high risk of developing type 2 diabetes now need to be put in place.