PurposeThis study serves two objectives; first, it examined the impact of ownership structure and board characteristics on firm value; second, the moderating effects of board gender diversity (women appearance on board) and board ethnic diversity (Chinese, Indian, and Foreign ethnicities) have been examined on the relationship between ownership structure, board characteristics, and firm value.Design/methodology/approachThe dynamic model, system generalized method of moments (S-GMM hereafter), is employed to control potential dynamic endogeneity, reverse causality, simultaneity and unobserved heterogeneity persistent in corporate governance-performance relationships during 2006–2017 of 483 Malaysian listed companies.FindingsFindings pertaining to objective one reveal that there is a weak linkage between ownership structure and firm value, whereas board characteristics significantly affect firm performance based on resource dependence theory. While considering the results of objective two, there is mixed evidence of moderating impact of board gender and ethnic diversity on ownership structure, board characteristics and performance nexus.Practical implicationsThe findings of the study are practically significant for regulatory bodies, namely, Bursa Malaysia, Securities Commission (SC) Malaysia, and policymakers to develop guidelines for ownership structure variables. Moreover, Malaysian firms need to disperse their concentrated ownership structure for enhanced firm value. In addition, board characteristics significantly affect firm performance in Malaysian listed companies.Originality/valueThe paper contributes to multiple aspects: first, it examined the impact of ownership structure and board characteristics on firm performance. Second, the moderating effect of board gender and board ethnic diversity contributes to research significant and valuable for the researchers and practitioners. Finally, the study employed S-GMM, controlling for dynamic endogeneity considered a main econometric problem for CG-performance relationships.