45 Nigerian Studies in Economics and Management Sciences 2018 ISSN: 2645-3061 Special Edition:45-55 Assessment of the Effect of Corporate Governance on Performance of Deposit Money Banks in Nigeria Adesina Olufemi Dadepo Abstract Background: The board of directors and the management must be conscious of its responsibilities to all stakeholders, the environment and the general society by complying with the appropriate legal, economic and institutional rules, practices and processes. This is the essence of corporate governance. Research Objective(s)/Hypothesis(es): The study assessed the effect of corporate governance on performance of deposit money banks in Nigeria. Data and Methods: Secondary data were collected from the annual report and accounts of the ten selected banks for a period of five years spanning from 2012 to 2016. Data collected were analyzed using descriptive statistics, correlation and regression analyses. Findings: The study revealed that board size (BZ) had positive and significant impact on return on equity (ROE) but insignificant impact on return on assets (ROA) while composition of independent and non-executive directors (BIND) exerted negative and insignificant impact on ROA. Concluding Remarks/Policy Recommendations: The study recommended that government and regulatory authorities must play a very good role in ensuring the compliance of banks to professional ethics and codes of Corporate governance. Keywords: Accountability, Performance; Stakeholders; Regulatory Authorities. Adesina Olufemi Dadepo is a Lecturer in the Department of Accountancy, The Federal Polytechnic, Ile-Oluji, Ondo State, Nigeria. E-mail olufemiadesina5@gmail.com.