Aims: We have previously published data from our public hospital Rhinology service indicating inequity in service provision, particularly with regards to patient ethnicity. In New Zealand, the SNOT-22 and Impact on Life (IoL) score are used to assess sinonasal disease severity and subsequent surgical prioritisation, however, their accuracy in reflecting disease burden across ethnic and socioeconomic groups remains unclear. This study evaluates the relationship between subjective (SNOT-22, IoL) and objective (Lund-Mackay (LM)) measures of chronic rhinosinusitis, and whether performance differs by ethnicity or deprivation. Methodology: A retrospective analysis of 273 patient's referred to a tertiary rhinology outpatient clinic in New Zealand was performed. Demographic data, SNOT-22, IoL score, and LM CT scores were obtained. Pearson correlation and Bland-Altman (BA) analyses assessed agreement between tools, further stratified by ethnicity and socioeconomic deprivation. Results: The cohorts ethnic and socioeconomic distribution was similar to the regional population. No differences in mean subjective or objective scores were observed across ethnic groups. SNOT-22 and IoL scores showed strong correlation, but poor agreement on BA analyses. Subjective tools demonstrated poor agreement with LM score; subgroup analysis was limited by small group size. IoL–LM correlation only reached statistical significance in NZ European group (r=0.307, p=0.025). LM scores showed significant differences by deprivation quintile (p=0.018), while subjective scores did not. Conclusion: This study found no evidence that SNOT-22 and IoL scores underestimate disease severity in Māori, Pacific, or socioeconomically deprived populations. Ethnic representation within the sample reflected regional demographics, but potential underrepresentation of high-need groups due to access barriers cannot be excluded. Limited subgroup sizes constrained further ethnic analysis.