Ankylosing spondylitis is a chronic and systemic disease involving the axial skeleton. In patients with involved cervical spine ankylosing spondylitis, endotracheal intubation by direct laryngoscope may be difficult because they have a limitation of cervical movement and anatomical anomalies. We experienced the evaluation of thirteen patients with involved cervical spine ankylosing spondylitis by the Mallampati classification, Cormack and Lehane grade, thyromental distance and orolaryngeal angle. By Mallampati class and Cormack and Lehane grade, patients were almost class 3 or 4. Thyromental distance was 5.3 +/- 0.4 cm, and orolaryngeal angle was 90.4 +/- 8.0o.