We created a simple experimental aneurysm by a minimal operative trauma performing the balloon-dilatation and the rupture of the abdominal aorta of animals. The aorta of minipigs was dilated under angiographic control until the rupture became visible. The abdominal aorta and its branches were mapped out and measured. The angiographics were calculated using a planimetric device. The dilatation of the aorta was increased up to 3.5 times the initial diameter when rupture occurred. The microscopical examination showed lesions in all three layers of the vessel only at the rupture site and some focal lesions of the tunica intima. This one-step procedure of producing an experimental aneurysm is done using a low operative trauma and allows testing of endovascular systems using only one anaesthetic.