A difference was obtained between cineventriculography and 2-D echocardiography in the determination of left ventricular volume and ejection fraction. Normal values obtained by the former could not be used for the latter. The authors, therefore, determined their own normal values. Apical 2-D echocardiography was used for the normal group (35 males, mean age 30.2 years; 20 females, mean age 26.2 years). In addition to mean values and standard deviations, one-sided tolerance limits (T) were calculated, separating the normal range from abnormal within 95% confidence limits for 90% of the total group. End-diastolic and end-systolic volume index in males was 66.8 +/- 8.8 ml/m2 compared with 26.9 +/- 5.2 ml/m2 on biplane evaluation. Tolerance limits were calculated at 82.0 and 35.9 ml/m2, respectively. Stroke volume index was 39.9 +/- 7.0 ml/m2, T = 27.8 ml/m2, ejection fraction 59.2 +/- 6.0%, T = 48.8%. End-diastolic and -systolic volume index for females had a mean of 60.7 +/- 12.5 ml/m2, T = 85.0 ml/m2, and 25.7 +/- 7.4 ml/m2, T = 40.1 ml/m2, respectively. Stroke volume index was 56.5 +/- 10.6 ml/m2, T = 35.9 ml/m2, the ejection fraction 58.1 +/- 6.5%, T = 45.5%. Between monoplane and biplane measurements of apical 2-D echocardiograms there was no significant difference. Normal values for volume and ejection fraction of the left ventricle, determined from apical four-chamber and RAO-equivalent cuts make it possible to categorize the function of the heart and to provide the basis for further studies of the sensitivity and specificity of the method.