This study aims to develop an understanding of the role of the extended audit report in mitigating managerial opportunistic behavior. Hence, this study examines the significance of Key Audit Matters (KAMs)disclosure in the rise of managerial bad news hoarding behavior, by decreasing the likelihood of stock price crashes. It also investigates the role of different aspects of audit firm characteristics in promoting the role of KMAs disclosure. This is achieved through examining the role of audit firm size, auditor industry specialization and audit tenure. The inferences are based on FTSE-193 firms with a total of 559 firm-year observations. The results reveal that the Big4 and industry-specialized audit firms, which disclose about KAMs in the previous year, have a negative impact on managerial bad news hoarding behavior, by decreasing the likelihood of stock price crash risk in the current year. Additionally, the findings suggest that KAMs disclosure is potentially compromised when an auditor has long audit tenure. These results are robust to additional controls and alternative measures. Overall, these results highlight the need for examining the information processing effect of KAMs disclosure and its role in controlling managerial opportunistic behavior.