We conducted a detailed investigation into retinal hemorrhages in renovascular malignant arterial hypertension experimentally produced in rhesus monkeys. The hypertension was produced by modified Goldblatt's procedures in 60 rhesus monkeys and hypertensive fundus changes were studied by ophthalmoscopy, stereoscopic color fundus photography and fluorescein fundus angiography. Our study revealed that, in hypertensive retinopathy due to malignant hypertension, retinal hemorrhages usually did not constitute either one of the earliest or one of the most conspicuous retinal lesions, but, on the contrary, were a minor feature of the retinopathy. Neither the time of onset of retinal hemorrhages nor their peak severity showed any significant correlation with the level of the arterial hypertension. The hemorrhages were usually situated in the nerve fiber layer, and could be located anywhere in the fundus but were usually found in the distribution of the radial peripapillary retinal capillaries. There was no association between the presence of retinal hemorrhages and retinal venous changes; the latter were seen only in a minority of animals and consisted of retinal venous stasis, venous collaterals and arteriovenous shunts.