The research examines how loan repayment failures affect the profitability of Nigerian commercial banks throughout the 32-year period 1992–2023. The Central Bank of Nigeria's 2023 statistics bulletin provided the secondary data used in the research. This paper uses an ex post facto design. Return on assets (ROA) was the dependent variable in this research, while non-performing loans (NPL), loan loss provision (LLP), and lending rate (LDR) were the explanatory factors. We tested the hypotheses using the Ordinary Least Squares statistical estimation approach. The outcome shows that non-performing loans have a negligible adverse effect on returns on assets. In Nigeria, loan loss provisions have a somewhat favorable effect on returns on assets. The return on assets is negatively and negligibly impacted by the loan default rate. A coefficient of determination of 0.737691 indicates that 74% of the return on assets can be attributed to the independent variables (non-performing loans, loan loss provision, and loan default rate), whereas 36.23% cannot be explained or included in the model. In the meantime, the modified R-square indicates that the whole model fits well. The research comes to the conclusion that loan repayment default significantly improves the viability of Nigerian commercial banks. To achieve economic development in Nigeria, the report suggests prudent non-performing loan management. Nigeria's central bank should regularly evaluate Nigerian commercial banks' lending practices. In order to successfully improve supervisory and regulatory tasks, it is also recommended that the supervisory authorities actively participate in capacity development.