The feasibility of three-dimensional echocardiographic reconstruction by semi-automatic border detection to assess left ventricular volume and function was investigated in a clinically applicable setting in 23 patients with various cardiac diseases and 7 normal volunteers. The commercial equipment permits digital acquisition of three apical orthogonal views, manual tracing of end-diastolic and end-systolic endocardium, semi-automatic border extractions of other frames, three-dimensional echocardiographic reconstruction and dynamic display within 20 min in a low resolution mode. Correlation of measurements with data obtained by magnetic resonance imaging (MRI) using the biplane modified Simpson method showed left ventricular end-diastolic volume (y = 0.894x - 0.456, r = 0.925, p < 0.001), end-systolic volume (y = 1.09x - 8.98, r = 0.959, p < 0.001), and ejection fraction (y = 0.956x + 1.93, r = 0.851, p < 0.001). In addition, a dynamic three-dimensional "movie-like" image displayed the shape, geometry, and regional wall motion abnormality, and change in global shape and size of the left ventricle. Three-dimensional echocardiographic analysis by three apical orthogonal views and dynamic display of the left ventricle provides reliable data comparable to MRI measurements within a reasonable period of time, and is now clinically feasible.