Ceramics of the nominal composition Bi2Zn0.1V0.9O5.35 and Bi2Ni0.1V0.9O5.35 were obtained. The crystal structure was examined by X-ray diffraction from room temperature to 973 K. TGA and DTA were done in air, nitrogen and oxygen between 370 and 970 K. For both ceramics TGA cycles indicate no visible change in sample mass during measurements. DTA curves, on the other hand, exhibit peaks due to phase transitions in both heating and cooling runs. The thermal heat effects per mass of examined material are stronger for BIZNVOX.10. The impedance of the ceramics with Pt electrodes was measured in the frequency range 5-10(7) Hz at constant temperatures between 410 and 980 K. The conductivity of the samples was determined by nonlinear least-squares analysis of the impedance spectra. The temperature dependence of the conductivities in Arrhenius type plots is presented. A change of slope of the total conductivity occurs for both materials. A time dependence of conductivity in a limited temperature range is observed only for BIZNVOX.10. The transition temperatures observed in DTA coincide with those observed in conductivity measurements. A phase transition, involving a reordering process of the oxygen ions, is considered responsible for this phenomenon.