Delirium in 3 elderly patients with recent cerebral infarction and pre-existing brain dysfunction receiving low dose propranolol is described. The dose ranged from 30 to 60 mg/day and the interval between delirium onset and drug initiation was 3-7 days. One patient exhibited ictal mydriasis and sinus tachycardia. Hypoalbuminemia was found in 1 patient. Discontinuation of propranolol abolished their delirious pictures 2-5 days later. Their delirium may be attributed to central beta blockade or anticholinergic effect. Preexisting brain damage, old age and hypoalbuminemia may predispose such patients to neuropharmacotoxicity of low dose propranolol.