Background and Objectives : Decannulation failure may result from factors such as inadequate ability 0 clear secretion, mucosal induration, granulation tissue, restenosis, tracheal wall depression and vocal cord palsy. We were to evaluate the effectiveness of surgical treatment on the basis of site and type of stenosis. Materials and Method : A series of 44 cases of decannulation difficulty between 1993 and 1997 were reviewed. The following data were collected on each of these patients : primary disease, indication for tracheostomy, site of stenosis, endoscopic findings of stenosis, surgical techniques used for treatment. Results : Primary diseases were 30 head trauma, 4 neck injury, 10 other diseases. Indication for tracheostomy were 37 prolonged intubation, 4 emergency tracheostomy, 3 laryngeal trauma. Endoscopic findings of stenosis were 24 granulation tissue, 16 laryngotracheal collapse, 4 combined with granulation tissue and collapse. Site of stenosis were 3 glottic, 9 subglottic, 24 stomal, 1 substomal, 7 mixed. 22 of 24 cases were decannulation using endoscopic treatment. Conclusion : The most common cause of failed decannulation was sternal granulation tissue. The most effective treatment of granulation tissue was endoscopic technique.