The effect of comminution techniques used during the powder preparation stage of zinc oxide varistor powder was studied. The continual requirement for downsizing in electronic components combined with improved performance, demand greater understanding of the parameters influencing the required characteristics. Improvements in energy absorption capability of low voltage zinc oxide varistors are highly desirable from both a commercial and end product performance perspective. Enhanced energy absorption capability can be used to upgrade the rating of an existing varistor form factor capable of suppressing larger transients (Product capability enhancement) or alternatively reducing the part dimensions (Cost improvements). Current commercial applications for zinc oxide varistors demand energy performance improvements especially in automotive and telecommunications applications, where dimensions and costs as well as high reliability are imperative to compete in the world marketplace. The physics of energy absorption indicates that in order to improve this, improvements must be made in thermal properties, material processing and testing. Materials parameters of interest include, uniform density, chemical homogeneity and grain size. A high degree of chemical homogeneity in the oxide powder mix prior to pressing and densification is required, in particular, particle size distributions of the oxide dopants and zinc oxide -oxide dopant mixture with maximum values < ljum are highly desirable. Varistors manufactured by the conventional ceramic process use comminution to achieve particle size reduction of oxide dopants, prior to their addition to the zinc oxide slip. This work compares the effects of using eight combinations of milling-mixing techniques on the particle size distribution of oxide dopants and the full formula slip, and examines the microstructural properties of the densified parts using scanning electron microscopy (SEM), and compares the energy absorption capabilities of the devices produced by each technique. The four comminution techniques studied were, Ball, Vibratory, Turbula, and Attrition milling. Shear mixing was used as in the conventional manufacturing process to mix the oxide dopants and zinc oxide. The work has shown that attrition milling is the most efficient comminution technique, reducing particle size distribution averages to well below ljum in less than two hours, compared to the other techniques which, regardless of milling time could not achieve the sub micron size distribution averages. In all samples where comminution versus shear mixing was used to mix-mill the oxide dopants and zinc oxide together, the energy capability was always considerably improved over the samples where shear mixing alone was used. This work has also identified Vibratory milling of oxide dopants followed by attrition milling of the oxide dopants and zinc oxide together, gave 12% better average energy absorption capability performance over the conventional technique. (Ball milling followed by shear mixing)