We studied zinc uptake by nonhuman primate retinal pigment epithelium (RPE) and choroid, usingwZn as a probe. With intravenously administeredMZnCl2, virtually all detectable tracer was lost from the plasma after 20 hours but the pigment epithelium-choroid showed prominent uptake and retention. Plasma concentrations of oral“ZnO remained high 20 hours after feeding. Uptake and retention of orally administeredMZn as“ZnO from the bloodstream by the RPE/choroid was avid in both young and old animals. Excretion in urine and feces was minimal. All pigmented ocular tissues took up and retained“Zn. A survey of total zinc content of human and nonhuman primate ocular tissues showed that the pigmented tissues had consistently higher concentrations of zinc. Our results demonstrate for the first time direct uptake and retention of zinc from the blood by primate RPE and other ocular tissues.