The paper aims to examine the moderating role of gender diversity within a corporate board on the relationship between tax aggressiveness and a firm’s corporate social responsibility (CSR) approach. This analysis was conducted using a set of indicators of financial statements of 168 Italian listed firms between 2011 and 2018. In addition, the sustainability reports of the same companies were observed. To perform the analysis a logit regression model is used. This paper shows different empirical results. First, this study notes that there is not a direct relationship between tax aggressiveness and CSR reporting. Second, gender diversity in a board of directors increases the orientation of companies to CSR disclosure, but does not have an impact on the relationship between tax aggressiveness and CSR disclosure. Instead, CEO gender has a positive influence on the relationship between corporate tax planning and CSR reporting in accordance with Global Reporting Initiative (GRI) standards. This study emphasizes the key role of gender diversity in the growth of the CSR approach and the reputation of companies. Therefore, governments and policymakers of major countries should promote gender diversity in corporate decision-making bodies, which contributes to achieving the Sustainable Development Goals (SDGs).