The aim of this study was to improve the understanding of the factors determining a firm's affiliation with the United Nations Global Compact (UN GC) as the largest voluntary corporate responsibility initiative worldwide. Drawing on the board perspective of the firm, this paper examines the effect of gender diversity and the mediating effect of the existence of a corporate social responsibility (CSR) committee. To test the paper's objectives, the authors use an international sample of analysis of 29,951 firm-year observations from 2012 to 2018. The results suggest that female directors on the board significantly encourage the firm's affiliation with the UN GC and support the mediating effect of the existence of a CSR committee. Therefore, the positive impact of female directors on UN GC signatories appears to be mediated by the existence of a CSR committee.