This study aimed to develop a three-dimensional (3-D) method for assessing ventilation/perfusion (V/Q) ratios in a pig model of hemodynamic perturbations using electrical impedance tomography (EIT). To evaluate the physiological coherence of changes in EIT-derived V/Q ratios, global EIT-derived V/Q mismatches were compared with global gold standards. The study found regional heterogeneity in the distribution of V/Q ratios in both the ventrodorsal and craniocaudal directions. Although global EIT-derived indices of V/Q mismatch consistently underestimated both low and high V/Q mismatch compared with global gold standards, the direction of the change was similar. We made the software available at no cost for other researchers to use. Future studies should compare regional V/Q ratios determined by our method against other regional, high-resolution methods.