Computer assisted surgery (CAS) has not been integrated yet in the surgical routine of reconstructive cranio-maxillofacial surgery. Modified software makes navigation systems applicable for the requirements in reconstructive surgery i.e. preoperative planning, virtual reconstruction, intraoperative navigation and postoperative control including restaging procedures in oncology cases. We report on 25 cases of orbital reconstruction among a total of 54 cases that were planned and operated using the STN-navigation system (Stryker-Leibinger). Using CAS the surgeon has the chance to virtually design the important reconstructive surgical steps prior to the operation; stereolithographic models can be completely replaced. During surgery the planned contours can be as well navigated as the position of the eye-bulb. In unilateral deformities mirroring of the unaffected side allows for ideal virtual reconstruction. Meanwhile the indications for using CAS on a routine base are extended from primary and secondary orbital corrections to skullbase tumors, in which the pretherapeutically definded safety margins are navigated during the operation, corrections of craniostenoses, complex bimaxillary orthognathic cases, minimal invasive biopsies at the skullbase, transethmoidal optic nerve decompression and insertion of zygomatic implants. Schlagwörter: computer assisted surgery, frameless stereotaxy, maxillofacial surgery, reconstructive surgery