The accuracy of laser drilled holes in metals is limited by a relatively large amount of molten material which is produced when lasers with pulse durations in the range of nanoseconds or longer are used. In general, shortening the pulse duration down to the picosecond or femtosecond regime promises to overcome these problems. In this contribution different influences on hole quality such as energy density, beam quality, and polarization as well as processing strategies for high precision drilling of steel with ultra-short pulses are presented and discussed. A new method of polarization control is demonstrated by which the hole geometry can significantly be improved and ripples in the surface of the hole walls can be avoided during helical drilling. Furthermore, results of investigations on the influence of the ambient pressure will be presented.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.