In Korea, diabetes mellitus, which causes micro and macrovascular complications, has been rapidly increasing during recent decades and has become a leading cause of disability-adjusted life years. The prevalence of diabetes mellitus was 12.4% in 2011 and that of prediabetes, a condition of high risk for developing diabetes mellitus, is 1.5- to 3-fold greater than that of diabetes. The diabetes prevention programs in other countries were shown to reduce or delay progression from prediabetes to diabetes mellitus. However, these results are not applicable to Korean people because of genetic and environmental differences. Therefore, we need to plan and perform a diabetes prevention study in Korean. Based on these results, we should design intervention tools for a Korean diabetes prevention program. We can consider several preventive interventions with lifestyle modification suitable for Korean people and pharmacologic treatments such as metformin or alpha-glucosidase inhibitor.