An open-chest canine model for acute experimental echocardiographic studies is described. The ultrasound transducer is placed on the exposed anterior epicardial surface, fixed in place to minimize transmitted motion or excessive pressure on the heart, and directed to record various intracardiac structures. Good recordings can be obtained from the interventricular septum, posterior left ventricular wall, and the mitral and pulmonic valves. Structure identification is facilitated by use of an ultrasound contrast technique. Alterations of normal motion in response to physiologic, pathophysiologic, and pharmacologic interventions can then be assesed. Potential uses of the model are discussed.