A theoretical study of the thermal decomposition and isomerization channels of alpha-bromoethoxy radicals is reported. Geometry optimizations were carried out at the MP2(full)/6-311G(d,p) level of theory and energetics were calculated using G2MP2 theory. Bond scission, intramolecular three-center HBr elimination and isomerization processes have been examined. Energy-specific rate constants k(E) and thermal rate constants k(T) under atmospheric conditions, were evaluated using Rice-Ramsberger-Kassel-Marcus theory. The calculations indicate that C-Br bond scission is the dominant decomposition channel, providing theoretical evidence for the previous experimental result. (C) 2003 Elsevier B.V. All rights reserved.