The present study was carried out on the adrenal glands of ten healthy adult donkeys of both sexes. The corrosion casts were prepared from eight adrenals by injection of a mixture of 4:1 Mercox and Methylmethacrylate. The adrenal glands of the donkey received their arterial blood supply through three main sources, the cranial, middle and caudal adrenal arteries. These arteries were distributed allover the gland surfaces and gave rise to several arteriolar branches in the loose layer of the capsule. Some of them formed the widely meshed capillary network (capsular plexus). The subcapsular plexus was formed from the rest of arterioles in addition to those of the capsular plexus. This plexus appeared in the form of convex lobules of densely meshed capillary network covering the arcs of the Zona arcuata. The Zona fasiculata was supplied by long straight parallelly oriented capillaries that continued downward with a little increase in the diameter forming the sinusoidal capillaries of the Zona reticularis and lastly join the capillary network of the adrenal medulla. The adrenal medulla received its blood from the direct continuation of the sinusoidal capillaries of the Zona reticularis as well as from the long cortical arterioles that gave rise to small collaterals to the cortex. In the medulla, the capillaries constituted a densely meshed network having an acinar form in the center and a widely meshed network at the juxtamedullary region.