In order to compare biplane left ventricular cast volume determinations from orthogonal and nonorthogonal axial oblique and standard orthogonal oblique cineangiograms to those that were obtained by water (H2O) displacement, we evaluated 14 human heart specimens in the following projections: 30-degree right anterior oblique and 60-degree left anterior oblique/20-degree cranial (LVa), 45-degree left posterior oblique and 60-degree left anterior oblique/30-degree cranial (LVb), and 30-degree right anterior oblique and 60-degree left anterior oblique (LVc). The correlation coefficients and standard errors of the estimate (SEEs) for the biplane orthogonal and nonorthogonal axial oblique (LVa and LVb, respectively) and standard orthogonal oblique (LVc) cineangiographic left ventricular volume determinations compared with the left ventricular cast volumes obtained by H2O displacement were similar (each r = 0.99 with SEEs = 5 to 7 milliliters (ml)). However, the mean biplane cineangiographic cast volume of 69 +/- 43 ml (SD) by LVa exceeded the average left ventricular cast volume of 60 +/- 35 ml by H2O displacement (p less than 0.01), while the average left ventricular cast volumes obtained with LVb and LVc (63 +/- 35, and 60 +/- 34 ml, respectively) did not differ significantly from the mean left ventricular cast volume obtained by H2O displacement. We concluded that the biplane orthogonal and nonorthogonal axial oblique cineangiographic views of the left ventricle, which have been reported to improve the delineation of cardiac anatomy, left ventricular regional wall motion, and the assessment of mitral regurgitation, also provide accurate determinations of left ventricular volume that are similar to those calculated from standard biplane orthogonal oblique cineangiograms.