This article considers the emergence of women's parties, their nature, and development in a comparative framework. Using an original dataset, this article documents and describes 30 such parties contesting elections at the national level in Europe since 1987. The article argues that women's parties are indications of failures of the established political parties to include and represent women's interests. The findings also demonstrated that women's parties are more likely to appear where women are empowered unevenly than where they are already included or their marginalization is consistent.