ObjectivesTo analyze the economic burden caused by delay in the diagnosis and treatment of diabetes.MethodsThe employee/non-employee health insurance and medical examination data from Japan Medical Data Center (JMDC) and Milliman Inc. were used to analyze the health economic burden of the situation in case the diabetic population receives timelydiagnosis and treatment with real world data.ResultsThe overall population delaying the diabetes diagnosis and treatment in Japan was estimated to be 916 000, and the average time of delay was 39.6 months. The increase in time of delay was related with the increase in monthly medical costs after diabetes diagnosis. If the whole delayed population could receive timely diagnosis and treatment, it can totally save about 38.24 billion yuan (1.5% of the annual Japanese national medical expenditure.ConclusionsThe current study suggests a huge potential health economic burden that can be improved by promoting the diagnosis and treatment of diabetes, which provides reference for the economic evaluation of similar health policies and also the application of real world data in China in future.