A simplified degradation model for the continuous gamma-irradiation of MEK in aerated aqueous solutions has been constructed using previously reported experimental studies and detailed kinetic model studies (Driver, P.A., %lowa, G.A., Wren, J.C., Radiat. Phys. Chem. 57(1), 37; Glowa, G.A., Driver, P.A., Wren, J.C., Radiat. Phys. Chem. 58(1), in press). The simplified model, consisting of only seven reactions and four equilibria, reproduces the experimental data and the full model results of the behaviour of MEK and the intermediate decay products and pH during the radiolysis reasonably well. The simplified model also reproduces the full model results on the dose profiles of water radiolysis products such as H-., e(eq)(-), (OH)-O-., O-2(-) and H2O2 very well. In this paper, the simplified model is described and the results are compared with the experimental data and simulation results from the full model. Crown Copyright (C) 2000 Published by Elsevier Science Ltd. All rights reserved.