The adrenergic innervation of the central retinal artery was studied in several species of the New World monkey. In all, a marked difference existed in the distribution of adrenergic innervation between the intraocular and the extraocular portions of the artery. In the orbit and in the optic nerve as far forward as the lamina cribrosa, the central retinal artery has a plentiful supply of adrenergic nerve fibers. Within the globe, the arteriolar branches of the central retinal artery are devoid of adrenergic innervation while the choroidal vessels in the same preparations are heavily innervated.