Delay in diagnosis of diabetes and pre-diabetes is a world-wide problem. A Thai outpatient study at a tertiary hospital found a delay in diabetes diagnosis (defined by Thai Clinical Practice Guidelines) in 96.9% of 260 study participants, and identified a particular problem in those with hypertension and those using non-cash insurance schemes. To try and identify those with diabetes or pre-diabetes as early as possible, guidelines published in 2022 jointly from the ADA and EASD suggest screening for type 2 diabetes should begin for all adults at age 35, and if the results are normal, testing should be repeated at a minimum of 3-year intervals. For those with risk factors including those with overweight or obesity, those with high-risk race/ethnicity, those physically inactive, those with hypertension, testing should begin at a younger age and occur at more frequent intervals. In children and adolescents who are overweight or have obesity, or who have risk factors for diabetes, testing should be considered after the onset of puberty. In Pakistan, the higher prevalence of type 2 diabetes among younger individuals has prompted National Clinical Guidelines to recommend screening for all individuals to start at age 30. The aim of screening asymptomatic adults for pre-diabetes and type 2 diabetes is to facilitate earlier detection, diagnosis, and treatment, with the ultimate goal of improving health outcomes by preventing the development of secondary complications, particularly blindness and kidney failure. However, there is uncertainty about the effects of screening for type 2 diabetes on all‐cause mortality and diabetes‐related mortality. There are also issues with take-up of screening – individuals from lower socio-economic groups in developed areas were less likely to take up screening for diabetes, despite the fact that these populations are likely to be at higher risk of non-communicable diseases. Education and community out-reach are important if screening is to achieve its potential. Research is needed to produce reliable and accurate biomarkers for diabetes and pre-diabetes that can be used in community screening anywhere in the world.