Regarding the anatomical variation of the branches of the arteries in different animals and the importance of New Zealand white rabbit as an animal model in researches, the brachiocephalic trunk and its major ramifications were studied in 20 New Zealand white rabbits by anatomic and ultrasonographic approaches. Ultrasonography was performed by using a linear probe with a frequency between 6 to 12 MHz. The major branches of the brachicephalic trunk were detected and their diameter measured. The rabbits were euthanized and embalmed by 10 percent formalin. The brachiocephalic trunk and its branches were dissected. The distances between the branches of the brachiocephalic trunk were measured and their diameters also were measured by caliper. Branching pattern of the brachiocephalic trunk of the rabbits were similar to what has been described by other authors. The ultrasonographical measurements of diameter for left subclavian, right subclavian, left common carotid, right common carotid and brachiocephalic trunk were respectively 1.86,2.02,1.38,1.43,2.88 millimeters and the anatomical measurements were 1.85,2.01,1.32,1.40,3.16 millimeters. It seems that the ultrasonographic examination of the brachiocephalic branches is a reliable method to estimate the size of these vessels in living rabbits but there was difference between ultrasonographic and dissection method in Brachiocephalic trunk.
