The examination of feminist research on political representation, public policy, and political institutions indicates that a shift in emphasis from the dichotomous variable of sex to the concept of gender is taking place. The shift is incomplete partly because many feminists believe both concepts are necessary to good research design. While mainstream political scientists have become more willing to use sex as a background variable in their research, they have not come to terms with notions of gender, a reluctance that may cause them to make important mistakes in their analysis of politics. Gender is a concept that suggests another major reexamination of what we think about political life. Its implications are insistent and far-reaching, offering a productive means of understanding politics.