Despite the numerous regulatory frameworks employed by the different financial regulators in various economies, the 2009 financial crisis that crumbled the world’s financial system could not be avoided. The Basel III framework became fully implemented by firms in the financial sector and the introduction of expected shortfalls served as substitute for Value at Risk. However, despite these various regulatory frameworks, operational activities kept fluctuating in the Nigerian economy. Thus, this study examined the effect of the implementation of Basel Accord III on the operational efficiency of listed banks in Nigeria. Data such as expected shortfalls, credit risk, market risk, and liquidity risk were collected from individual selected banks and were analyzed using the fixed effect regression model. The result showed that expected shortfalls affects operational efficiency negatively (-0145). The findings also revealed that credit risk (0.099) and liquidity risk (0.00008) positively influence operational efficiency in Nigeria. It was concluded that the implementation of Basel III framework in Nigeria negatively influences operational efficiency. Thus, there is a need for banks to embrace the effective use of expected shortfalls in order to minimize bank risk, especially in the capital market.