Approximately 347 million persons were estimated to have diabetes worldwide in 2008, an increase of 194 million cases from 1980. Diabetes now affects both high- and low-income countries, with low-income countries bearing the majority of the burden. The epidemiologic transition from traditional health risks, such as poor hygiene, to modern health risks, such as sedentary lifestyle, has facilitated the increase in incidence in diabetes, especially in developing countries. The effect of these risk factors may be especially pronounced in some racial and ethnic populations. Increased surveillance for diabetes has contributed to increased diabetes prevalence in higher-income countries. Survival with and some risk factors for diabetes have improved in developed countries, but global diabetes mortality has increased by 20 % since 1990. Population growth and aging will only increase the burden of diabetes, and public health interventions are needed to address diabetes risk factors to stem the tide of this epidemic.