ObjectivesTo explore the associations of air pollutants and Air Quality Index (AQI) with risk of sudden sensorineural hearing loss (SSNHL)DesignCross-sectional studySettingMedical record data and local population data collected between 2014 and 2022 in Changshu, China were retrospectively reviewed.ParticipantsAdults aged 18 years and above who were diagnosed with SSNHL in Changshu No. 1 People’s Hospital or Changshu No. 2 People’s Hospital from the spring of 2014 to the fall of 2022 were included in the study.Outcome measureSSNHL was diagnosed by clinicians using the Chinese diagnostic criteria for SSNHL.ResultsCompared with those exposed to the lowest tertile of carbon monoxide (CO), the prevalence ratio for those exposed to middle and high tertiles of CO were 1.113 (95% CI 1.022 to 1.213) and 1.230 (95% CI 1.105 to 1.369), respectively. The risk of SSNHL was increased by 30.6% (95% CI 9.9% to 55.4%) per doubling increment of CO. No categorical association was found between ozone (O3) exposure and risk of SSNHL, however, an increased risk of 22.2% (0.8%–48.2%) was identified for each doubling of O3. No association was identified between other pollutants and AQI and risk of SSNHL.ConclusionsIn this study, CO and O3were associated with an increased risk of SSNHL in Changshu, China. Further studies are warranted to confirm our findings.