AIMS: To identify individual and general practitioner (GP) characteristics associated with potential over- and undertreatment of hyperglycaemia in type 2 diabetes and with HbA not being measured. METHODS: A cross-sectional study that included 10233 individuals with type 2 diabetes attending 282 GPs. Individuals with an HbA measurement during the last 15 months were categorized as potentially overtreated if they were prescribed a sulphonylurea and/or insulin when the HbA was less than 53 mmol/mol (7%) when aged over 75 years or less than 48 mmol/mol (6.5%) when aged between 65 and 75 years. Potential undertreatment was defined as age less than 60 years and HbA > 64 mmol/mol (8.0%) or HbA > 69 mmol/mol (8.5%) and treated with lifestyle modification and/or monotherapy. We used multilevel binary and multinominal logistic regression models to examine associations. RESULTS: Overall, 4.1% were potentially overtreated, 7.8% were potentially undertreated and 11% did not have HbA measured. Characteristics associated with potential overtreatment were as follows: long diabetes duration, prescribed antihypertensive medication, cardiovascular disease and renal failure. Potential undertreatment was associated with male gender, non-western origin and low educational level. Characteristics associated with not having an HbA measurement performed were male gender, age < 50 years and cardiovascular diseases. GP specialist status and GPs' use of a Noklus diabetes application reduced the risk of not having an HbA measurement performed. CONCLUSION: Potential overtreatment in elderly individuals with type 2 diabetes was relatively low. Nevertheless, appropriate de-intensification or intensification of treatment and regular HbA measurement in identified subgroups is warranted.