The laser surgical treatment of carcinomas of the upper aerodigestive tract has become an established treatment modality at many otolaryngology departments throughout the laser years. The oncologic results that can be achieved with this surgical technique are quite as good as the results that can be achieved by conventional surgery, the functional results on the other hand often seem to be superior to conventional surgery. The Nd:YAG laser has so far rarely been used as a cutting device in the head and neck region. The fibertom mode is a new technique, which has been developed to make the employment of the Nd:YAG laser as a laser scalpel feasible. Between December 1995 and May 1997 thirty-five patients with squamous cell carinomas of the oral cavity were treated at the Department of Otolaryngology, Head and Neck Surgery of the University of Kiel with the Nd:YAG laser in fibertom mode (30 - 50 Watt, cw-mode, 600 m bare fiber). The operative approach, intra- and postoperative complications, duration of the operation and of the healing process, as well as functional and oncologic results were documented and compared to the retrospectively raised data of a group of patients (n equals 25), that was treated by CO2 laser surgery. When working with the Nd:YAG laser in fibertom mode fewer hemorrhages during the actual dissection could be observed as opposed to dissection with the CO2 laser. By laser dissection with the Nd:YAG laser in fibertom mode the operation had to be interrupted to a much lesser extent for bipolar cautery, thus resulting in a reduced operation time. Until a complete reepithelialization of the laser wound was achieved an interval of 3 - 4 weeks went by. Following Nd:YAG laser excision the healing process was 7 - 10 days delayed when compared to CO2 laser surgery. The functional and oncologic results were quite satisfactory in both groups and no major difference between the two laser systems could be observed. The fibertom mode renders the use of the Nd:YAG laser for the excision of tumors in highly vascularized regions like e.g. the tongue, the floor of the mouth and the oropharynx. The functional and oncologic results which were achieved with this method in the treatment of carcinomas of the tongue are so convincing that the CO2 laser has been replaced in our department by the Nd:YAG laser for the indications mentioned above. Tumors of the larynx and hypopharynx on the other hand remain to stay a domain of CO2 laser surgery.