Introduction Mitomycin C is a natural antibiotic that has been used to inhibit the proliferation of fibroblasts in scar tissue. Objective To evaluate the effectiveness and safety of topical Mitomycin C as an adjuvant in the endoscopic treatment of laryngotracheal stenoses. Data synthesis A systematic review of experimental or observational studies that have evaluated the treatment of laryngotracheal stenoses with the use of topical Mitomycin C was performed. Databases researched: LILACS, PubMed, Embase, Cochrane and Web of Science. Outcomes: resolution (symptom-free time ≥ one year), number of procedures required, and complications resulting from the procedure. A total of 15 studies (involving 387 patients) were selected. Mitomycin C was administered to every patient in 11 studies, and in 4 other studies, the patients were separated into 2 groups, 1 receiving mitomycin C, and the other not. The resolution of the stenosis evaluated in 12 studies in which the patients received mitomycin C was of 69% (95% confidence interval [95%CI]: 61-76%; I2 = 17.3%). A total of 52% of the patients (95%CI: 39-64%, 11 studies; I2 = 64.7%) were submitted to a single endoscopic procedure, and 48% (95%CI: 36-61%, 11 studies; I2 = 64.7%) were submitted to more than 1 procedure. Complications (mediastinal and subcutaneous emphysema, dysphonia, laceration or vocal fold paralysis and acute light obstruction) were reported in 9% of the patients (95%CI: 3-18%, 9 studies; I2 = 79.8%). Conclusions The evidence suggests that mitomycin C is an effective and safe option in the endoscopic treatment of laryngotracheal stenosis.