We have generated a set of thermodynamic and kinetic parameters for the reactions involving HO2 in the very early stages of benzene oxidation at low temperatures using density functional theory (DFT). In particular, we report the rate constants for the reactions of HO2 with benzene and phenyl. The calculated reaction rate constant for the abstraction of H C6H5 by HO2 is found to be in good agreement with the limited experimental values. HO2 addition to benzene is found to be more important than direct abstraction. We show that the reactions of HO2 with the phenyl radical generate the propagating radical OH in a highly exoergic reaction. The results presented herein should be useful in modeling the oxidation of aromatic compounds at low temperatures. (C) 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.