In this article we present a case of aortic balloon valvuloplasty in a 6-year old dog. The diagnosis of severe aortic stenosis was made by transthoracic echocardiography while the interventional procedure was monitored by transoesophageal echocardiography and fluoroscopy. Angiography was found to be a reliable method for measuring the valve annulus. A ventricular tachycardia of 220 beats/minute, induced by a pacing catheter introduced into the right ventricle, prevented dislocation of the valvuloplasty balloon during its dilation, thereby avoiding injury to the valve leaflets or surrounding tissues.