Chondrosarcomas are a rare disease of the bone and the soft tissue, which often impress in the area of the facial bones as a painless swelling. They speak very poorly to a radiotherapy or chemotherapy. Radical surgical resection with the greatest possible safety margins is the treatment of the first choice. We present a case of a 34-year-old patients with the upper jaw chondrosarcoma. Preoperative MRI and CT-diagnostics showed a pronounced tumor growth with intraorbital, ethmoidal, nasal expansion and involvement of the skull base. The tumor diameter was up to 7 cm. In the clinical examination, an extreme displacement of the eyeball was manifested anteriorly and superiorly, as well as a facial swelling and disturbed vision at the right side. After presentation of the patients in our tumor conference, we chose a tumor resection with preservation of eyeball and a postoperative adjuvant heavy ion therapy. The tumor resection was done over a transfacial access under microscope- and navigation-guided surgery with preservation of the eyeball. The reconstruction of the orbital floor and the maxillary sinus was made with a titanium mesh. The special challenge was to prevent the correct position of the previously extremely repressed eyeball. The post-operative course was uneventful and the cosmetic and functional results were very satisfactory. Also the visual disturbances have been significantly improved. Due to the extensive tumor size and the small safety distances in the skull base and the bulb, adjuvant radiotherapy was carried out with heavy ion radiation. With navigation and microscope-guided surgical techniques also extremely large and the bulb displacing chondrosarcoma can be operated with good functional and aesthetic results. Keywords: Chondrosarcoma, Maxillary bone tumor