BACKGROUND: Almost all anesthesiologists are encounter a difficult airway occasionally, which is probably the most important cause of anesthesia related morbidity and mortality. The intubating laryngeal mask airway (ILMA; FastarachTM; laryngeal mask company, Henley-on-Thames, UK) is a new device for tracheal intubation. It is an ideal rescue airway since it can be placed quickly and used as a conduit for endotracheal intubation, while ventilation is ongoing. This prospective study was underttaken from January, 1997 to December, 2004 to evaluate the appropriateness of the ILMA for anticipated or unanticipated difficult airways. METHODS: After institutional committee approval, seventy eight patients were enrolled in this study. The anticipated group compromised thirty five patients and the unanticipated group forty three. In the unanticipated group, anesthesia was induced with thiopental sodium and vecuronium and maintained with enflurane or isoflurane, whereas in the anticipated group, awake intubation with nerve block was done before intubation. The success of the technique (within five attempts), the number of attempts, the durations of the successful attempts, and adverse events (desaturation, bleeding) were recorded. RESULTS: The rate of successful tracheal intubation with ILMA was 92.7%. The numbers of attempts and the times to success were not significantly different between the two groups. Adverse events occurred significantly more frequently in the unanticipated group. Conclusion: The ILMA is a useful device for the management of patients with a difficult airway and may be a valuable alternative to direct laryngoscopy or fiberoptic intubation when neck movement is unfavorable or in those with an unanticipated difficult airway.