Contents of polychlorinated dibenzodioxines, oxide composition and grain size distribution of com. CuO produced by oxidation of Cu(2)O and other Cu-contg. (waste) materials were discussed to develop methods for improving the product quality. The dioxins were removed by anaerobic heating of the product at 1073 K. The CuO content was increased by increasing the oxidation time, recirculation of the product and a fine grinding of the raw materials. The CuO grain size distribution was improved by use of adequate sieves.