To evaluate the utility of single and biplane right ventricular (RV) contrast angiograms, we evaluated 25 canine RV casts and 31 cineangiograms performed in patients during standard contrast ventriculograms. Both standard single and biplane formulae were utilized. In the 25 canine RVs, absolute volume was determined by water displacement. Both biplane (r = 0.96) and single-plane (r = 0.86) volumes correlated well with cast data. These formulae were then applied to contrast ventriculograms in the 31 patients (30-degree right anterior oblique and 60-degree left anterior oblique projections). The ejection fractions (EFs) calculated from the single-plane technique provided fair correlation with EFs derived from the biplane data (r = 0.81, y = 0.81X + 0.05). Similar correlations were noted when end-diastolic volume results were compared (r - 0.78, y - 0.57X + 56.4). However, while single-plane contrast right ventriculograms correlate with estimates of global RV function and size by biplane methods, considerable scatter of the data may limit its application in individual cases.