We investigated gender differences in the association between gender-segregated peer preferences and sexism in adolescents (15-17 years, 60 boys and 85 girls). To assess gender-segregated peer preferences, adolescents nominated peers for interaction in two contexts: "hanging out" at home and working on a school project. The Modern Sexism Scale [Swim, J. K., K. J. Aikin, W. S. Hall, and B. A. Hunter. 1995. "Sexism and Racism: Old-Fashioned and Modern Prejudices." "Journal of Personality and Social Psychology" 68 (2): 199-214] measured two dimensions of sexism: Antagonism towards Women's Demands (believing feminist issues are unimportant) and denial of continuing discrimination (believing gender discrimination no longer exists). For boys, Antagonism towards Women's Demands was associated with gender-segregated peer preferences in the school and home context. For girls, Denial of Continuing Discrimination was associated with gender-segregated peer preferences in the home context. Results are informative for educators and for other professionals interested in reducing inequality and sexism among adolescents.