PURPOSE: To describe the detailed technique for producing experimental carotid aneurysms in dogs and the success rate, cause of failure and remedy, based on our experience. MATERIALS AND METHODS: Fourteen male dogs weighing 12-15kg were anesthetized with inhalation of 1-2% halothane and 50% nitrous oxide. Each surgical procedure was performed under sterile condition with the aid of an operating microscope. A paramidline incision 7-8 cm in length was made parallel to and medial to the external jugular vein in the dog's neck. The externaljugular vein was harvested as a 1cm vein pouch by ligation and division of the proximal and distal ends. The ipsilateral common carotid artery was exposed and clamped at both ends by a vascular clamp. A 5-mm long elliptical arteriotomy was made at the mid portion of the artery, and then end to side anastomosis between the artery andvein sac was performed by using interrupted 7-0 monofilament prolene sutures. Carotid arteriography or Doppler sonography was performed 1-6 weeks after aneurysm construction. RESULTS: Twenty experimental aneurysms we reconstructed, and 17 aneurysms were patent on follow up study, but one dog with two aneurysms died from hemorrhagicpneumonia 17 days after surgery. The overall patency rate was 75%. CONCLUSION: We demonstrated the feasibility of creating experimental aneurysm models in the dog and expect that the technique presented will help to avoidfailure in the construction of aneurysms.