The standardized operational techniques available today make it possible to perform extensive surgeries for the treatment of craniofacial malformations and advanced tumors in this anatomically complex region. The new techniques of computer-assisted surgery allow us to interactively use the three-dimensional image data of the patient during surgery. Simulation of complex osteotomies in individual patients is now possible with the aid of new software developments for virtual cutting and shifting of bone segments. Intraoperative realization with navigation systems has been performed at our clinic for the past 4 years, and we have gained extensive experience from more than 100 clinical applications of mechanical and optoelectronic navigation systems. These passive localization systems supply the surgeon with direct intraoperative support while performing the surgeries. It is the primary goal of computer-assisted surgery to support the surgeon during diagnosis, operational planning, and intraoperative navigation. We can thereby achieve a reduction in operational risk and duration, which in turn results in a considerable stress reduction for the patient.