New measurements of the electrical conductance of single crystals of olivine during creep in the temperature range 1325--1725 K, under controlled oxygen fugacity and under uniaxial stresses of 60--180 MPa, are discussed. These measurements indicate a small but definite increase in the conductivity of olivine as a result of creep. This increase is weakly correlated with strain and stress. The change in conductivity of olivine that results from deformation is not diminished by annealing at high temperature. Similar measurements on corundum crystals lend support to the measured increase in olivine conductivity. These results suggest that dislocations do not directly act as channels for enhanced conduction in olivine; however, they may indirectly influence conduction through their interaction with other defects. Possible mechanisms to account for this influence include interactions between dislocations and point defect complexes and destruction of the preexisting cellular arrangement of dislocations with redistribution of impurities. The present study suggests that deformation is not a viable mechanism in producing high-conductivity layers in the upper mantle. ¿ American Geophysical Union 1989