The complete atmospheric oxidation mechanism of 1,2-dibromoethane is proposed. There are 32 species and 22 transition state species involved in the proposed mechanism. Geometry optimizations and frequency computations are performed using the second-order Møller-Plesset perturbation theory and the 6-31G(d) basis set for all species and transition states. Single-point energy computations are performed using fourth-order Møller-Plesset perturbation theory and coupled cluster theory. Potential energy surfaces, including activation energies and enthalpies, are determined from the computations. Final products of this degradation include OH, CO(2), CO, CH(2)(O), CH(O)CH(O) (glyoxal), bromine radicals, CH(O)Br, HOBr, and a reservoir for a new atmospheric compound, BrC(O)C(O)Br.