The oxygen-ionic conduction in the YSZ|YSZ and YSZ|YSH bicrystals, where YSZ and YSH are single-crystalline solid solutions of, respectively, ZrO2 and HfO2 with 12 mol % Y2O3 are studied using the impedance method. Bicrystals consist of two single crystals separated by a common intercrystalline boundary. The direction of the applied electrical field is chosen perpendicular to the intercrystalline boundary. The oxygen-ion transfer in the bicrystals is determined primarily by the transport processes in the bulk single crystals. This is associated with a fast exchange by oxygen vacancies between single crystals at the intercrystalline boundary.