3,4-Dichloroaniline (3,4-DCA) is an aromatic amine and is a model environmental contaminant. It is an important precursor for the synthesis and degradation product of several herbicides. It is a metabolite of commonly applied herbicide, 3,4-dichloropropionanilide or propanil. Biodegradation kinetics of 3,4-DCA has been reported. Mechanism of degradation of aqueous 3,4-DCA in a novel dielectric barrier discharge plasma reactor has been studied. 1,2-dichlorobenzene, 2-chloro-1,4-benzoquinone, 3,4-dichlorophenyl isocyanate, 2-chlorohydroquinone, 3,4-dichloronitrobenzene and 3,4-dichlorophenol were identified as degradation intermediates by GC-MS analysis.