The microsurgical anatomy that provides the basis for dealing with lesions arising in the petroclival region was reviewed in 15 adult cadaver heads and 25 dry skulls. The eight surgical approaches studied were the retrosigmoid, extreme lateral transcondylar, translabyrinthine, transcochlear, combined supra and infratentorial presigmoid, subtemporal anterior transpetrosal, subtemporal preauricular infratemporal, and the postauricular transtemporal approach. Considerations important in the selection of these approaches are discussed. Special attention was directed to the course of the facial nerve and internal carotid artery in the temporal bone and the major venous pathways draining the region.