The main findings related to the localization and physiological roles of calbindin D_28k, since its discovery in brain in 1974 until the present, will be reviewed in this article. Special emphasis will be given to the distribution of this protein in cerebellum and retina, as compared to other calcium binding proteins such as parvalbumin and calretinin and other proteins involved in intracellular Ca²⁺ movement. More detailed statements regarding the localization of calbindin D_28k in the visual pathways of mammals and avian will be described in normal conditions or after deafferentation.