Selective catheterization of blood vessels aided by fluoroscopy has been a common procedure in man for the last ten years. Special catheterization technics have also been developed for some animals, especially the dog and cat (2, 4, 6). In 1933, Rousthoi (7) performed his classical experiments with arterial catheterization in the rabbit. Introducing a cannula or a catheter into the common carotid artery and gently passing it down into the aorta, he was the first to visualize the coronary arteries in a living animal by an injection of contrast material nonselectively into the ascending aorta. The present report describes a technic for selective arterial catheterization in the rabbit. Method and Material The technic employed is as follows: An ear vein of the rabbit is cannulated with a pediatric scalp vein needle and Diabutal or urethane anesthesia is administered. Physiologic saline with heparin (1,000 I.U. per 500 ml) is used for rinsing the catheter. The catheter employed is made of a small radiopaque vi...