The effect of Er2O3 addition on electrical conductivity of c-ZrO2 was investigated by analyzing the impedance spectra of undoped and various amounts of Er2O3-doped cubic zirconia (c-ZrO2). The undoped and 1-15 wt% Er2O3-doped c-ZrO2 powders were prepared via colloidal process. The doped powders were then pelletized under a pressure of 200 MPa. In addition, the undoped and Er2O3-doped c-ZrO2 specimens were sintered at 1500 A degrees C for 1 h. The electrical conductivity of the specimens was measured using a frequency response analyzer in the frequency range of 100 mHz-13 MHz, in the temperature range of 300-800 A degrees C. Electrical conductivity results indicate an increase in the conductivity with increase in the test temperature. The addition of 1 wt% Er2O3 into c-ZrO2 led to an increase in the grain interior, grain boundary, and total conductivities. The distortion caused by the addition of Er3+ cations in the c-ZrO2 lattice leads to an increase in the concentration of oxygen vacancies in the c-ZrO2 matrix, resulting in an enhancement in the electrical conductivities.