The purpose of this article is to investigate the relationship between board gender diversity and corporate financial performance by presenting evidence from studies conducted in developed and emerging markets. Additionally, we review the literature on gender quota legislation that requires the appointment of female directors on corporate boards. Other variables that commonly affect the relationship between board gender diversity and corporate financial performance are discussed, including board leadership structure, board activity, board independence, firm size, and leverage. Our findings from reviewing the studies examining the impact of board gender diversity and gender quota legislation on firm performance are mixed and inconclusive, strongly influenced by the methodologies applied in these studies. Few advanced studies have recently applied the complexity theory by using the Fuzzy Set Qualitative Comparative Analysis technique, backed by Boolean algebra & configurational relationship, to examine past inconclusive results. By moving away from multiple regression analysis and applying a more qualitative methodology, their results were able to reveal that high corporate financial performance can be achieved via different complex paths and combinations of antecedent conditions. These findings can result in significant revisions to corporate governance best practices and board gender quota recommendations. Our study contributes to the existing literature on board gender diversity and sheds light on the factors that influence corporate financial performance, while also providing insights to regulators on the potential reconsideration of gender quota legislation.