The cerebral arterial circle is a polygonal shape-like arterial anastomosis placed in the brain base, where it rounds the optic quiasm and the tuber cinereum, and also related to the interpeduncular fossa and the anterior perfurated substance. It is formed by the proximal parts of the anterior, middle and posterior cerebral arteries, and the right and left posterior communicating arteries. In order to describe the cerebral arterial circle disposition we investigated the brains of twenty rats. For each animal, the heart left ventricle was probed and acetone, distilled water at 37 °C and a solution of Neoprene Latex "450" stained with a specific red pigment were injected in sequence into it. To fix the brain in a better way, we isolated the head and made an aperture at the dorsal wall of the cranium and the whole specimen was fixed in a 15% formaldehyde solution. We took off the brain from the skull with the aid of a cold light source monocular magnifier. To take the photographic data we used a semi-professional camera. The results showed that the cerebral arterial circle in rats is formed by branches of both internal carotid arteries and of the basilar artery, and is closed rostrally by the rostral communicating artery, and caudally by the right and left terminal branches of the basilar artery. We concluded from our data that the cerebral arterial circle in rats is compound by branches of both internal carotid arteries and basilar artery, and that it is rostrally and caudally closed.