Efficient CO2laser drilling of copper sheet has been obtained following pretreatment with excimer laser radiation at intensities of (1–2)×106W cm−2. The present studies show a significant reduction in the laser pulse energy, pulse duration, and gas assist parameters required to drill copper sheets with thicknesses of up to 1 mm. Optimization of laser drilling under these conditions involves a material removal regime that differs from that obtained at high laser intensity when drilling untreated surfaces.