A total of 40 patients (163 examinations) with severe motor and intellectual disabilities were enrolled for videofiberscopic investigation of granulation tissue in the trachea. Their ages ranged from 2 to 52 years (mean:23.2 years). Seven out of 11 patients (63.6%) with an endotracheal tube and 17 out of 21 patients (81.0%) with a tracheostomy tube had tracheal granulation tissue. The tracheal granulations were mainly located near the tip of the tube and tended to develop on the anterior wall of the trachea. For the treatment of the granulation tissue, the tube was changed to an adjustable cannula in 9 cases and laser ablation was done in 6, with relapse occurring in 5 and 4 cases, respectively. Local application of mitomycin C achieved a good outcome in 2 relapsing cases. Tracheal deformity due to torticollis, cervical lordosis, and thoracic deformity may cause tracheal granulation tissue in patients with severe motor and intellectual disabilities. In addition to changing the tube length and/or laser ablation, local application of mitomycin C may be a useful treatment for tracheal granulation tissue.