The dopamine (DA) receptor has had an interesting history. Unusual actions were attributed to the catecholamine for many years, but these effects were generally considered to be manifestations of activation of 0.and ,8-adrenergic receptors rather thap results of action of DA on a specific receptor (1). The pendulum now has swung the other way. The literature is replete with papers reporting the existence of DA receptors subserving specialized functions in a wide variety of organs and species (2-4). A pertinent question which must be answered is whether the same DA receptor subserves all reported functions or whether there is a family of specific, but different, DA receptors (5). In this review we are concerned primarily with similari­ ties and differences in the effects of agonists and antagonists acting on the DA receptor in the canine renal vascular bed and on selected DA receptors described in other organs and species. The actions of DA on a specific vascular receptor and on other receptors in the cardiovascular system have been the subject of previous reviews (1, 6, 7).