Do gender quotas positively affect public gender egalitarianism defined as the public support for gender equality? Does the influence differ by regime types of countries? Moreover, does the introduction of gender quotas improve the conducive impacts of women’s civil society participation on public gender egalitarianism? Along with the dramatic increase in women’s descriptive representation after the diffusion of gender quotas across the globe, more work should be done to generalize the influence of gender quotas on public attitudes toward gender equality with a cross-national timeseries data. This article based on panel regression models conducts a cross-national time-series analysis on 117 countries from 1972 to 2019. Relying on role-model effect and normative effect theories, this article demonstrates that there is a positive relationship between the adoption of reserved seat gender quotas and public attitudes toward gender equality. The average treatment effects (ATEs)estimated from the nearest neighbor matching strategies are also statistically significant. More interestingly, this article shows that the influence of gender quotas is heterogeneous across different regime types. In addition, this article unveils that the conducive impact of women’s participation in civil society organizations on egalitarianism is magnified by the adoption of gender quotas.