In this paper, the influence of the atmosphere on the ablation rate of Al2O3-TiC ceramics using nanosecond duration pulses of 248 nm laser radiation and He, Ne, N-2, air, Ar and Kr atmospheres, at pressures between 10(-4) and 1 bar, was investigated. The effects of plume confinement due to ambient gas and the mechanisms of laser light attenuation are discussed. Analytical and numerical models were developed and used to explain the observed reduction in the ablation rate with increasing atomic/ molecular weight of the ambient gas and its pressure. (C) 2002 Elsevier Science B.V. All rights reserved.