1. Oral administration of dl-α-tocopheryl nicotinate (EN) (0·04 or 0·2 mmol day —1 kg —1 ) or dl-α-tocopheryl acetate (EA) (0·2 mmol day —1 kg —1 ) delayed the progress of hypertension in unilaterally nephrectomized rats, which were treated with deoxycorticosterone and salt, and in genetically hypertensive rats (SHR) which were given sodium chloride solution. Suppression of body weight gain, incidence of pneumonia and mortality were reduced by treatment with EN or EA. 2. Severe hypertension in old SHR (9 months) further progressed, when drinking water was replaced by sodium chloride solution, and four out of ten of these animals died of cerebral haemorrhage during 4 weeks. The administration of EN or EA prevented the increase in blood pressure and incidence of stroke.