The vascular anatomy of the head and neck of eight adult helmeted guineafowl (Numida meleagris) was investigated by latex injections and dissection, resin casting, and lipidol injections and X-ray photography. The vascular anatomy of these regions is similar to that of the domestic fowl Gallus domesticus, the main differences being in the helmet, wattle and cere vascularization, and the presence of a nape-cheek rete in N. meleagris. It is postulated that five vascular arrangements in the head and neck are important in brain temperature regulation. These arrangements are: the nape-cheek rete, the temporal rete, fine arteriovenous networks in the wattles and cere, and the cavernous sinus-intercarotid association. All but the last of these arrangements require pathways of blood flow to the brain other than the most direct route. Such pathways are discussed.