Obstruction of the upper airway caused by laryngotracheal stenosis (LTS) often results in severe morbidity and even mortality. Treatment of LTS continues to present a challenge and a wide array of surgical techniques have been employed. Despite multiple endoscopic and/or open reconstructive procedures, patients often experience restenosis as a result of the abnormal wound-healing process that initially instigated the airway obstruction. The high rate of stenosis relapse has therefore motivated researchers to find new methods to modulate and control the wound-healing process of the airway. Although other adjuvant treatments such as steroids and antibiotics have been investigated in LTS, much attention in recent years has turned to the use of topical mitomycin-C (MMC). As a topical application, MMC has been shown to inhibit fibroblast proliferation in wound-healing processes. The use of MMC in the treatment of airway stenosis was first reported in 1998 and is now routinely used in the endoscopic management of LTS. However, despite numerous animal and human studies, the benefit of MMC in LTS patients remains questionable. While previously published retrospective data suggest that the addition of MMC improves outcome, there have been no prospective studies to directly address the efficacy of MMC in endoscopic LTS surgery. This study will be the first randomized, prospective, double-blind, placebo controlled clinical trial designed to investigate the efficacy of MMC as an adjunctive therapy to endoscopic surgical treatment in patients with LTS. In addition, the study will investigate the relationship between patient symptoms and objective pulmonary function measurements. Ultimately, the results of this study may influence the treatment and evaluation of patients with laryngotracheal stenosis.