Hypertension combined with diabetes in the elderly is characterized by many important metabolic and cardiovascular changes, among which insulin resistance, hyperinsulinaemia and increased total peripheral resistance appear to be the most relevant. Non-insulin dependent diabetes mellitus is also characterized by insulin resistance and hyperinsulinaemia. Moreover, hyperinsulinaemia itself has been shown to increase total peripheral resistance. Hyperinsulinaemia thus seems to play a key role in the pathophysiology of hypertension in elderly diabetic subjects. Therefore elderly hypertensive diabetic patients should be treated with thiazide diuretics in low doses, calcium channel blockers and alpha-adrenergic blockers.