Effect of capital structure on profitability in case of Nigerian deposits money bank, which is a core business operation is the main focus of this research. For a period of ten years (2008-2017) panel data were being collected for ten deposits banks of Nigeria. Panel data were mainly collected from the financial statement. Data analysis through SPSS resulted that short-term debt to asset, measurement of capital structure is negatively associated, whereas profitability has a positive correlation with long term debt to asset. Finally, total debt to asset shows negative association with profit in a statistically significant manner. Suggestions like reduced debt financing, increased equity financing have been provided such that cost of financing can be maintained at a minimum level. Finally, recommendations for improving overall performance have been highlighted through this research.