This study used quarterly data to investigate the impact of capital structure on the performance of four Microfinance banks in Cross River State. The microfinance banks are UNICAL Microfinance Bank, Ekondo Microfinance Bank, Living Spring Microfinance Bank and CRUTECH Microfinance Bank. The data collected were analyzed using both descriptive and quantitative methods. The descriptive methods employed simple tables and percentages to analyze trend performance of the major variables captured in the study. The study adopted the Ordinary Least Squares (OLS) estimation technique to conduct quantitative analysis. The reason for employing the classical Ordinary Least Squares (OLS) is that of all classes of estimators, the Ordinary Least Squares (OLS) is the Best Linear Unbiased Estimator (BLUE) and it has minimum error. The OLS possesses some salient features such as unbiasedness, efficiency, Best Linear unbiasedness, Least or minimum variance, least mean square error and sufficiency when compared with other econometric estimators. The results of this study were analyzed using economic a priori criteria, statistical criteria and econometric criteria.