The d.c. conductivity (sigma) of V2O5-SnO-TeO2 glasses prepared by the press-quenching method was studied at temperatures from room temperature (RT) to 473 K, and the effect of annealing on sigma was investigated. The conductivity of 50V(2)O(5) . 20SnO . 30TeO(2) glass was determined to be 3.98 x 10(-4) S cm(-1) at 473 K and was unchanged for annealing (6-48 h) at 493 K, lower than T-g = 501 K, while its density increased with annealing time. These glasses were found to be n-type semiconductors, and the conduction was confirmed to be due to adiabatic small polaron hopping for V2O5 greater than or equal to 50 mol %, and non-adiabatic for V2O5 < 50 mol %. The activation energy for conduction, W, decreased with annealing time. Variations in oxygen molar volume of the glasses with annealing time inferred a change in glass structure, from loosely to closely packed, resulting in a decrease in vanadium ion spacing with annealing. This caused an increase in the polaron band width, producing a decrease in polaron hopping energy and W. The effect of annealing time on the density of 50V(2)O(5) . 20SnO . 30TeO(2) glass was explained adequately by Winter’s formula.