Serum lmmunglobulin and Complement Levels in the Patients With Head and Neck Carcinoma and the Evaluation of Autoantibody Positivity Ratein this study, smooth muscle antibody (SMA), anti-nücleer antibody (ANA) anti- mitochondrial antibody (AMA), anti-parietal cell antibody (PA), antiglomerular basal membrane antibody (GM), serum immunglobulins and complement-C3 levels have been searched. The positivity rate of ANA (31.91 %) and SMA (38.29 %) were found high in sera of the patients with head and neck carcinoma which had been diagnosed histopathologically. But the positivity rate of AMA (4.25 %) PA (12.76 %) and GM (2.12 %) were low in the same group. ANA and SMA were detected in 1 O of 30 patients with laryngeal carcinoma; ANA were detected in 5 of 9 patients (55.5 %) and SMA were found in 4 of 9 patients (44.5 %) with nasopharyngeal carcinoma. There was no significant deviation in the levels of immunglobulins and complement-C3. The highest levels of immunoglobulins have been detected in patients with laryngeal carcinoma. Finding of high positivity rate of ANA and SMA in the patients with head and neck carcinoma showed an accordance with the other investigators' results.