The purpose of this work is to examine the interaction of members of the board with financial knowledge on the association among capital structure with firm financial performance in the Nigeria DMBs. Empirical studies were reviewed to scrutinize the upshot of capital structure in connection to the performance of firms. As the result of the foregoing, this study introduces board financial literacy as a moderator variable to interact between capital structure with performance of firms. A correlational design was adopted. Population and sample size of the study consists of 13 listed DMBs on the floor of Nigeria Stock Exchange for the period 2012 to 2021. Fixed effects regression model was employed to analyse the data of the study. Diagnostic test was conducted to confirm the validity of the statistical inferences of the study. The result shows that BFL moderated the correlation involving DEFR with financial performance. Also, the result found that EFR and DEFR were not significant to the firm financial performance of DMBs in Nigeria. This work recommends that board members with financial literacy should come up with effective policy towards encouraging debt financing in their entities by effective supervision so as to enhance the overall firms’ financial performance as well as safeguarding shareholders interest. Research in future should replicate this topic in a domain other than DMBs.