Cilio-retinal arterioles are branches of the posterior ciliary arteries which supply areas of inner retina contiguous with the optic disc in about 20 per cent of individuals (Hayreh, I963a). The cilio-retinal territory is spared from ischaemic necrosis after occlusion of the central retinal artery, while infarction of retina supplied by cilio-retinal arterioles may accompany ischaemic swelling of the disc when the posterior ciliary arteries are occluded in temporal arteritis (Hayreh, i969). Only two cases of retinal infarction in the cilioretinal distribution have so far been described in association with occlusion of the central retinal vein (Oosterhuis, I968; Hayreh, 197I), although such cases are not rare. The purpose of this paper is to present a series of Io further cases together with a case of cilio-retinal infarction associated with a hemisphere branch retinal vein occlusion. The interrelationships between retinal vein occlusion and impaired posterior ciliary perfusion are discussed in the light of our findings.