The right ventricle was studied in 75 anatomically normal swine hearts, using, in all, nine geometric and volumetric parameters: ventricular-wall thickness, length of the right-ventricular inflow and outflow tracts, and volume of the right-ventricular inflow and outflow tracts. The data for these parameters were compared with previously published patterns for human hearts and volumetric data were compared with patterns of normality found in human hearts. As in the human heart, the ventricular inflow tract in swine hearts was significantly shorter than the outflow tract (P < 0.0001).