The Sarbanes-Oxley Act mandates public companies to establish internal control systems and assess their effectiveness. Quarterly reports by all companies and annual reports by companies with less than $75 million public float (non-accelerated filers) do not require auditor’s attestation while annual reports by companies with $75 million or more public float (accelerated filers) do require such auditor attestations. Quarterly reports should provide early warning of any impending material weakness (MW) to be disclosed in subsequent annual filings. This dissertation explores three types of “surprise” MW disclosures—positive, negative and no surprise—and consequences of such surprise disclosures. In part one, I document the frequency of surprise MW disclosures and internal control factors that are associated with each surprise type by filer status. Results show that 78 (77) percent of accelerated (non-accelerated) MW disclosures are negative surprise MW disclosures during 2004-2016. Entity level MWs are more associated with no-surprise rather than negative or positive surprise MW disclosures. In part two, I examine some consequences of surprise MW disclosures. The results show that companies with MW disclosures are more likely to dismiss their auditors and CFOs, and experience more shareholder voting against auditor ratification, compared to companies that issue clean reports. Auditor dismissal and CFO turnover are equally likely at negative and no-surprise MW disclosure companies. However, negative surprise accelerated filer companies’ shareholders are more likely to vote against auditor ratification than no-surprise accelerated filer companies. The third essay investigates the association between MW disclosures and audit fees. The results indicate that there is a significant positive association between audit fees and MW disclosures. Further, the results show that audit fees are higher at no-surprise companies than at negative surprise companies. The fourth essay focuses on audit report lag. The results indicate that MWs are associated with increased audit report lags, for both accelerated and non-accelerated filers. Further, surprise MW firms are more likely to experience increased audit report lag than no-surprise MW firms. Overall the results suggest that adverse internal control reports have consequences, and that the consequences vary between surprise and no-surprise MW firms. The results provide relevant empirical evidence to the ongoing debate on the necessity and efficacy of SOX Section 404 requirements.