The observable weaknesses in corporate governance of companies and the cases of accounting and audit failures have heightened concern of investors about corporate reports. This has led to the need for the establishment of Audit Committees to ensure the credibility of financial statements. This study seeks to evaluate the impact of Audit Committees (AC) on the performance of listed Deposit Money Banks (DMBs) in Nigeria. The specific objectives of the study are to evaluate the impact of components of Audit Committees (size, independence, meetings and financial expertise) on return on assets, net interest margin, Tobin's Q, financial standard compliance, and investors' confidence of Deposit Money Banks in Nigeria. The study employs qualitative and quantitative research methods using correlation and survey research designs. Panel regression and the Kendall's coefficient of concordance technique of data analysis were used for the analysis. The population of the study includes all the listed Deposit Money Banks. 

The secondary data was analysed using sample size of 16 through census sampling technique. The primary data was analysed using a sample size of 281 from a population of 950 members of registered shareholders' Associations using Yamane (1968) formula. 

The study reveals a significant positive relationship between components of audit committee (size, independence, meetings and financial expertise) and the performance of listed deposit money banks in Nigeria, and that audit committee function has significant positive impact on investors' confidence. Specifically, the findings reveal that financial performance during the period improved with the presence of Audit Committee member who is an expert in accounting and finance, which implies that an increase in the audit committee by one member increases financial performance significantly. Also an increase in the independent non-executive directors in the audit committee membership by one member enhances the financial performance significantly. The findings further suggest that an enhanced frequency of audit committee meetings drives the financial performance significantly, suggesting that the higher meeting frequency of the committee, the higher the financial performance. 

The study as well reveals that holding excess assets by the banks reduces profitability, and that the opinion of the Audit committees' discussions enhances the quality of managements' decision making. It is glaring that the audit committee has taken appropriate steps to ensure internal and external audit cooperate appropriately to ensure the completeness of assurance coverage and compliance with laws. 

The study therefore, recommends that there should be strategy towards creating enabling environment for improve the sustainability of Audit Committee for enthronement of good corporate governance practices, increase in the number of non executive independent members of the Audit Committee, increase in the frequency of meetings and that Banks should align their philosophies in such a way that Audit Committee members' education be entrenched to improve the quality of compliance decisions. The independence of audit committee must be deepened, with a true essence of regulation and the right assurance of improving investors' confidence.