Left ventricular volume would be useful in the diagnosis and treatment of patients with various heart diseases. So we measured left ventricular volume index using gated blood pool nuclear cardiac angiography which was easy to perform, non-invasive, and capable of repetitive studies. These left ventricular volume indices were compared with left ventricular volumes by quantitative cardiac cine-angiography and the results were as follows, 1. The correlation coefficient between left ventricular volume indices and left ventricular volumes was 0.829 (p<0.001). 2. The correlation coefficient between left ventricular volume indices and absolute left ventricular volumes which were obtained by measurement of cardiac output of patients. 3. There were good correlation in intraobserver and interobserver analysis.