This paper presents the changes of electrical characteristics in zinc oxide varistors subjected to hydrostatic pressure up to 4 kbar. Electrical measurements have been carried out with pressurized samples. Beyond 1 kbar, the leakage current increases exponentially with pressure as described by the relationshipIF=P7,4. This leads to a decrease, by a factor of 2, of the nonlinear coefficient. In spite of choosing a different experimental approach and different material compounds, our results are in very good agreement with those already published.