Background- The giraffe has been described by the physiologists as having a spectacular mammalian adaptation to browsing on tree leaves. With a five to six foot (150cm) long trachea which is two or more inches wide (5cm) in diameter, the giraffe would have a large anatomical dead space amounting to more than 2.8 liters. Compared to man’s anatomical dead space volume of 0.15 liters, the ... [Show full abstract] respiratory system of the giraffe probably experiences a very high resistance to air flow. Materials-Lungs were obtained from three adult Maasai giraffes (Giraffa camelopardalis), six calves (Bos indicus), three adult goats (Capra ibex) and three camels (camelus dromedarius). Measurements of the lungs were obtained and the pulmonary arterial system was dissected until the segmental arteries. Results-The giraffe had five lobes in the right lung and four in the left lung. While the calf and the goat had four in the right lung and three lobes in the left lung. The camel appeared to have three lobes in each lung. The study also showed that in contrast to the goat, calf and the camel, the distribution of the pulmonary arterial system of the giraffe illustrated a regular dichotomous pattern. Conclusion- This study postulates that the regular dichotomous distribution pattern of the giraffe pulmonary arterial system coupled with the highly lobulated lung may aid in maintaining a viable perfusion - ventilation ratio in the long necked giraffe.