Thirty-one consecutive patients with retinal arterial obstruction were studied with digital subtraction angiography (DSA). Among the 29 patients in whom DSA was technically acceptable, 45% (13/29) demonstrated evidence of carotid stenosis or an atherosclerotic plaque ipsilateral to the eye with the retinal arterial obstruction. In 21% of cases (6/29 patients) the stenosis was 60% or greater. The incidences of carotid atherosclerosis were similar among the central and branch retinal arterial groups.