Comfort discussing sex with friends may develop over time and may be associated with individual and peer characteristics. The current paper uses longitudinal data to examine the developmental trajectory and between- and within-person correlates of peer sexual communication quality. Participants were 434 college students (52.1% female, 38.7% European American/White, 32.5% African American/Black, 28.8% Latino American/Hispanic; M = 18.0 [SD = 0.4] years old fall of first year) who completed surveys at four semesters. Peer sexual communication quality improved across the college years, and tended to be higher during semesters when late adolescents held less conservative attitudes about sex and communicated about sex more frequently. Additionally, peer sexual communication quality was better among women and late adolescents who were sexually active at more semesters. We discuss implications for peer-led sexual health intervention programs and for theories of normative sexuality development.