Introduction: Subglottic stenosis (SGS) is a potentially life-threatening condition characterized by inflammation of the subglottic region which progresses to fibrosis/narrowing of the airway. Common symptoms include dyspnea, cough, stridor and dysphonia. Current standard of care is endoscopic laser surgery with dilation of idiopathic SGS (iSGS) under general anaesthesia for symptoms relief. The purpose of this study is to review the effect of serial adjuvant in-office intralesional steroid injection (ISI) on surgery free interval in SGS patients. Methods: Retrospective review of patients diagnosed with SGS from 2001-2022 were included. Electronic medical records were reviewed to collect demographic data, comorbidities and treatment received. The primary outcome measure is the effect of ISI on surgery-free intervals (SFI-measured in days) of SGS patients at an academic tertiary centre over a 20-year period. Results: Eighty-two patients with SGS were identified that underwent primary surgery from 2001-2015 after which, serial ISI was implemented as an optional adjuvant therapy. A subset of patients with indolent iSGS had little change in their clinical course. However, the majority of patients realized an increase in surgery-free interval with adjuvant ISI. Conclusions: The study demonstrates that serial adjuvant in-office ISI does increase surgical-free interval in the majority of SGS patients