OBJECTIVES:Serial intralesional steroid injection (SILSI) is an emerging treatment for idiopathic subglottic stenosis (ISGS), providing improvement in both subjective symptoms and objective airflow parameters. Little is known about how this airway remodeling affects the voice. This project analyzes subjective voice changes after SILSI and correlates these with airflow parameters. METHODS:An ISGS database containing voice-related quality of life (V-RQOL) and spirometry (peak expiratory flow percentage [%PEF]) was retrospectively queried. Included were ISGS patients from 2009 to 2019 who had at least one SILSI treatment. Encounters without complete data were excluded. Differences between preprocedure and postprocedure metrics were calculated. Correlations and nonparametric bivariate analysis were performed. RESULTS:Six hundred and seventeen steroid injections were performed in 55 patients, with an average of 3.5 years of follow-up. The average V-RQOL for all patient encounters, both pre- and postprocedure, showed little subjective dysphonia (83.5 of 100, 95% confidence interval [CI] 81.6 to 85.4). Considering SILSI-only treatments, there were 143 encounters with full data; of these, V-RQOL improved in 70 (49.0%), did not change in 40 (28.0%), and worsened in 33 (23.0%). Average V-RQOL improvement for the entire cohort was 1.9 points (95% CI: 0.7 to 3.2), which was small but significant (P = .0003). Across all data, there was a weak but significant correlation between PEF% and V-RQOL (ρ = 0.22, P = .0043). CONCLUSION:SILSI was associated with improvement in subjective voice ratings in about half of patients, and the improvement correlated with improved airflow measurements. This research adds to the growing body of data regarding SILSI and suggests that further work on functional changes to the larynx with airway remodeling is imperative. LEVEL OF EVIDENCE:4 Laryngoscope, 131:366-369, 2021.