The aim of this study was to review lifestyle modification interventions and pharmacological clinical studies designed to prevent diabetes and provide evidence-based recommendations for the prevention of Diabetes Mellitus. A review of relevant literature compiled via a literature search (PUBMED) of English-language publications between 1997 and 2010 was conducted. It is found that people at increased risk of developing type 2 diabetes mellitus can halt the development of the disease. Lifestyle modification intervention with reduction of 5%-10% of excess body weight and increase in moderate physical activity by 150 min/wk has consistently proven to reduce the appearance of diabetes in different at-risk populations. Pharmacologic interventions have also demonstrated the prevention of the appearance of diabetes in persons at risk. Bariatric surgery has decreased the appearance of diabetes patients in a select group of individuals. The progression from prediabetes to diabetes mellitus can be prevented. Lifestyle modification intervention changes with weight loss and increased physical activity are currently recommended for the prevention of diabetes.