This research work is based on the contribution of the computerization of the banking system to the development of modern banking in Nigeria. The Nigeria financial industry and the banking sector, in particular, are undergoing changes in recent times. The undergoing of the industry has also its financial implications in the country. It has introduced several risks and opportunities competition within the banking industry demands the need for a dynamic and innovative approach to the management of information system. The banking world is being influenced by information technology. Although computer as a veritable tool to improve banking facilities has not actually been adopted by all banks. The research is going to show the actual contribution of computers to the banking industry and the tools to improve banking facilities have not actually been adopted by all banks. In trying to state the contribution and problems related to computers, the researcher both primary and secondary data from finding, it was that computerization of the banking industry has contributed to the banking industry also bank efficiency. The research questions were also tested which shows that computerization of the banking industry in Nigeria has improved bank performance and efficiency.