Although binegativity, the stigmatization of bisexuality, is prevalent among heterosexual and lesbian and gay communities, little research has addressed how the quantity and quality of intergroup contact affects binegativity. Drawing on intergroup contact theory, this study examined contact with and attitudes toward bisexuals among heterosexual undergraduates, heterosexual adults, and lesbians and gay men. Knowing more bisexuals (quantity) predicted more positive attitudes toward and decreased intergroup anxiety with male and female bisexuals. A multilevel structural equation model indicated that contact quality simultaneously predicted higher perceived stability of female bisexuality (but not male bisexuality) and tolerance of and less intergroup anxiety with male and female bisexuals when contact quantity was controlled for. This research suggests that both quantity and quality of contact with bisexuals predicts improved intergroup attitudes. Implications for future research on reducing binegativity are discussed.