With its significant contribution to economic development and progress, the banking sector is crucial to every economy. The banking industry is sensitive and fragile, necessitating careful oversight. This study was conducted because it is consistent with this viewpoint. The general objective of the study is to access the effect of corporate governance code on financial performance of quoted deposit money banks in Nigeria. Proxy values for the variables were utilized to conduct the study. In order to assess the instrument's reliability, hypotheses were developed, population samples were collected, and multi regression analysis was used to establish the link between the dependent and independent variables. The findings revealed that there is no significant relationship between corporate governance and financial performance of quoted deposit money banks in Nigeria. The reasons include ineffective examination, inadequate legal reforms, poor compliance to financial reporting standards, political manipulations and huge corruption enshrine in the economic system. On this basis, recommendations were made, special body is to be set up by CBN to monitor compliance, legal reform be instituted to enforce compliance, professional ethics must be enforced, political manipulations must be avoided by all stakeholders and creating enabling economy environment through objective investigations and reporting on efficiency of  corporate governance code in those banks.