Using an open chest canine model, a method was developed for three-dimensional reconstruction of the contracting left ventricle from two-dimensional echocardiograms, which is applicable to intraoperative studies in humans. A mechanically held 5 MHz transducer was used to record parallel high resolution cross-sectional images with precise spatial registration. Myocardial borders were tracked manually and entered into a computer system. Regional filling and interpolation routines were applied to reconstruct the endocardial and epicardial surfaces of the ventricle. The myocardium can be displayed as a translucent, shaded three-dimensional solid surrounding the ventricular cavity. One or both surfaces can be rotated about any axis, sectioned through any plane and viewed in motion through systole and diastole. Studies before and after left anterior descending coronary artery occlusion showed the three-dimensional extent of abnormal left ventricular cavity and myocardial deformation. Quantitative examination of regions of interest permits the analysis of global and regional volumetric and myocardial thickness changes throughout the cardiac cycle. Thus, open chest three-dimensional echocardiography provides a powerful tool for the quantitative physiologic investigation of the left ventricle.