Breakdown voltages and electronic current data (at constant voltage) for anodic titanium oxide films in contact with aqueous electrolytes of varying concentrations and compositions have been obtained at 308 K. Both breakdown voltage and electronic current depend on electrolyte concentration, resistivity and composition. A linear relation between breakdown voltage and logarithm of electronic current has been observed. The effect of electrolyte concentration, composition and resistivity on breakdown voltage has been discussed in terms of the Ikonopisov electron avalanche breakdown model and the theory of Di Quarto and coworkers. The major factor contributing to the decrease in breakdown voltage with increasing electrolyte concentration is the increasing primary electronic current j0.