To estimate the global health expenditure on diabetes among people aged 20-79 years for the years 2010 and 2030.Country-by-country expenditures for 193 countries, expressed in United States Dollars (USD) and in International Dollars (ID), were estimated based on the country's age-sex specific diabetes prevalence and population estimates, per capita health expenditures, and health expenditure ratios per person with and without diabetes. Diabetes prevalence was estimated from studies in 91 countries. Population estimates and health expenditures were from the United Nations and the World Health Organization. The health expenditure ratios were estimated based on utilization and cost data of a large health plan in the U.S. Diabetes expenditures for the year 2030 were projected by considering future changes in demographics and urbanization.The global health expenditure on diabetes is expected to total at least USD 376 billion or ID 418 billion in 2010 and USD 490 billion or ID 561 billion in 2030. Globally, 12% of the health expenditures and USD 1330 (ID 1478) per person are anticipated to be spent on diabetes in 2010. The expenditure varies by region, age group, gender, and country's income level.Diabetes imposes an increasing economic burden on national health care systems worldwide. More prevention efforts are needed to reduce this burden. Meanwhile, the very low expenditures per capita in poor countries indicate that more resources are required to provide basic diabetes care in such settings.