Adrenal activity is stimulated and secretion of stress hormones is increased during advanced stages of renovascular hypertension. The literature suggests that the neuropeptide, cocaine and amphetamine regulated transcript (CART), might regulate adrenal secretory function and thus could influence its activity. We assessed potential quantitative and qualitative changes in the cells that contained CART in the adrenal glands of rats with renovascular hypertension. The renal arteries of ten rats were subjected to a clipping procedure, i.e., two-kidney one-clip (2K1C) model of arterial hypertension, and after 6 weeks each rat developed stable hypertension. CART was localized using immunohistochemistry. CART was detected in a large population of cells in the medulla, sparse nerve fibers in the cortex and the capsule of the adrenal gland. The population of CART-positive cells in adrenal glands of two kidney-one clip (2K1C) treated rats was greater and their immunoreactivity was increased compared to controls. Similarly, the length, width, area and diameter of CART-immunoreactive cells were significantly greater in the hypertensive rats than in controls. We demonstrated that renovascular hypertension alters the number and immunoreactivity of CART-containing cells in adrenal glands.