In countries around the world, constitutional protections of women's rights have provided a legal foundation to combat discriminatory laws, customs, and actions and a catalyst for advances in gender equality. This article draws on newly available data from 191 countries to analyze women's constitutional rights across the spheres of general equality and nondiscrimination, political participation, social and economic rights, family life, and customary and religious law. We examined how gender-specific and universal protections differed according to a constitution's year of adoption and last amendment, and identified regional patterns that persisted across all decades. Women were explicitly guaranteed general equality or nondiscrimination in 81% of constitutions, some aspect of political equality in 32%, marital equality in 27%, some aspect of work equality in 26%, and equal educational rights in 9% of constitutions. Protection of women's rights increased substantially between 1980 and 2011. As of June 2011, however, no constitution in the Middle East and North Africa guaranteed gender-specific protection in education, work, or marriage, and there were no guarantees of marital equality in South Asian constitutions. Of the constitutions that protected some aspect of gender equality, 5% stated that customary or religious laws could prevail over constitutional provisions.