It is close to 20 years since the authors began the collaboration that led to ambivalent sexism theory and its associated measure, both reviewed in their 1997 "Psychology of Women Quarterly" article, "Hostile and Benevolent Sexism: Measuring Ambivalent Sexist Attitudes Toward Women." This article reports the development and validation of the Ambivalent Sexism Inventory (ASI), an instrument for researching sexist attitudes. From a theoretical perspective, the authors hope that their analysis of the structural underpinnings of sexist attitudes inspires new ways of thinking about the complexities of gender relations, especially the perils of "positive" prejudice toward women, as well as the ambivalences involved in other prejudices.