This study aims to investigate the mediating role of job burnout in the relationship between organizational climate and audit performance within audit firms. The research is applied in nature with respect to its objective and is descriptive-survey in terms of data collection methodology. The statistical population comprises 1,879 officially certified and actively practicing auditors affiliated with audit firms that are members of the Iranian Association of Certified Public Accountants. A sample size of 319 participants was determined using Cochran’s formula and subsequently examined. The measurement instruments for organizational climate, role clarity, audit quality, and audit performance were adapted from Hegazy et al. (2023). Responses were recorded using a five-point Likert scale. Construct validity was employed to establish the scale's validity. Confirmatory factor analysis (CFA) was used to assess construct and content validity of the research instruments. Reliability was evaluated through Cronbach’s alpha and composite reliability; coefficients exceeding the threshold of 0.7 indicated acceptable reliability. Structural equation modeling (SEM) was applied to examine the relationships among variables, utilizing SPSS 25 and Smart PLS 4 software packages. The findings indicate that auditors’ organizational climate exerts a statistically significant positive effect on audit performance, although it does not significantly influence audit quality. Furthermore, organizational climate has a significant positive impact on auditors’ job burnout. Conversely, job burnout demonstrates a statistically significant negative effect on audit performance, while showing no significant effect on audit quality.