The destruction of organic model substances by indirect electrooxidation was investigated. The oxidation agent Co(III) was used because of the high redox potential of the Co(III)/Co(II) redox couple (E(0) = 1.808 V). Experiments were performed in a batch and in a continuous electrolytic cell by using various model substances (especially phenol and different chlorophenols). Intermediate and final products of the oxidation were identified and quantified. Organic carbon is ultimately transformed to CO2 and to small amounts of CO. The residual carbon in the process solution was determined by TOC measurement to be about 20 ppm. Organic chlorine is oxidized via chlorate to perchlorate. The remaining amount of adsorbable organic halogens (AOX) was less than 3 ppm. Based on these results, a pilot plant was constructed and is presently in operation.