Undertreatment of risk factors in patients with type 2 diabetes is common. We assessed the influence of elevated levels of blood pressure, total cholesterol, and A1C on decisions of Dutch general practitioners to change drug treatment in a cohort of 3,029 patients during a 1-year period. Respectively, 58, 71, and 21% of patients remained untreated despite poor blood pressure, lipid levels, and glycemic control. Of poorly controlled but already drug-treated patients, 52% did not receive intensification for antihypertensive medication, 81% not for lipid-lowering medication, and 43% not for glucose-lowering medication. We observed a significantly lower treatment intervention rate in moderately than in poorly controlled patients for blood pressure. This was not seen for decisions on cholesterol or A1C results. The low overall action rates observed for blood pressure and especially lipid management cannot sufficiently be explained by the use of treatment thresholds higher than those indicated by guidelines.