Al2O3-TiC ceramic composites are promising materials for micromechanical components. However, due to their hardness, brittleness and contraction during sintering, they are difficult to shape into high-accuracy parts using conventional forming techniques, Laser micromachining can be an alternative technique to shape this type of materials. Previous work using KrF (lambda = 248 nm) excimer lasers showed that micromachining was accompanied by the formation of a thin melted layer of resolidified material and, in certain conditions, a cone-like surface topography. This was explained by the different ablation behaviour of Al2O3 and TiC. To verify this assumption, Al2O3-TiC, Al2O3 and TiC ceramics were processed with a XeCl (lambda = 308 nm) excimer laser and their ablation behaviour was investigated. It was found that TiC has a higher ablation rate than Al2O3. The experimental results suggest that chemical reactions occur during processing of Al2O3-TiC in air and that cone formation can be due to the shielding of laser radiation by the resulting compounds.