The removal of diesel particulate matter (PM) is experimentally carried out using two types of uneven dielectric barrier discharge (DBD) reactors driven by positive-negative pulse voltage power supplies. One uneven DBD reactor is fed with exhaust gases from a diesel engine at the exhaust gas temperature and another uneven DBD reactor is fed with PM dispersed in a gas mixture of oxygen and nitrogen at room temperature, where PM was collected from the exhaust gases of the diesel engine. PM emission rates, PM sizes, and PM oxidation products are measured using a PM emission rate monitor, a particle size spectrometer, and a gas chromatograph at various discharge energy densities. It has been found that most of PM is oxidized completely into gaseous products of CO and CO2 under plasma discharge conditions. (c) 2007 American Institute of Chemical Engineers.