We present a measure, the Ambivalence toward Men Inventory (AMI), that differentiates between women's hostile and benevolent prejudices and stereotypes about men. The Hostility toward Men (HM) and Benevolence toward Men (BM) subscales of the AMI tap conventional attitudes toward men that have opposing valences. Each subscale assesses subfactors concerning men's power, gender differentiation, and heterosexuality. Three studies with predominately White, male and female participants (two with undergraduates and one with a community sample) establish the factor structure, reliability, convergent validity, and predictive validity of the AMI. The AMI was strongly related to its sister scale, the Ambivalent Sexism Inventory (Glick & Fiske, 1996) and to two established scales of attitudes toward men (Downs & Engleson, 1982; Iazzo, 1983). Only the AMI, however, successfully distinguished between subjectively positive and subjectively negative beliefs about men. A copy of the 20-item AMI is provided as a tool for further exploration of women's ambivalence toward men.