We study whether gender norms—proxied by Switzerland’s 1981 referendum on constitutional gender equality—continue to shape women’s entrepreneurship today, despite major demographic change. Using startup data for all Swiss municipalities from 2016 to 2023, we find that places with stronger historical support for gender equality have significantly higher women-to-men startup ratios. A one–percentage point increase in the 1981 “yes” vote share is associated with a 0.165 percent increase in this ratio. The result is robust to controlling for later gender-related referenda, extensive municipal characteristics, and contemporary policy measures. The association is stronger in municipalities with more stable populations and in less religious municipalities. Childcare spending alone is not linked to startup rates, but it positively affects women’s entrepreneurship when combined with supportive historical gender norms, highlighting the joint role of formal policies and informal social support.