The high incidence of difficult tracheal intubation in patients suffering from Obstructive Sleep Apnea (OSA) has been proved by many studies. The currently available screening tests for prediction of difficult tracheal intubation have only poor to moderate discriminative power when used alone. Combinations of individual tests add some incremental diagnostic value. Assessment of the predictive ability of some other methods such as acoustic pharyngometry and lateral cephalometry may be helpful.