We used latent growth curve analysis to extend research on associations between early puberty and adverse peer relations by examining the role of pubertal timing in the developmental trajectories of peer victimization and offending from early- to mid-adolescence. We made use of three-wave longitudinal data collected annually from a cohort of Swedish adolescents (N = 1,515, 51% girls, [X-bar] age at T1 = 13.0 years). The results revealed negative developmental trends for peer victimization and offending. Early pubertal timing was linked to higher initial levels and a steeper decrease of peer victimization and offending. The only effect of pubertal timing that differed between the genders was that the initial level of offending was stronger for boys than girls. In conclusion, the negative impact of early pubertal timing on peer victimization and offending occurs in the early stages of adolescence and disappears thereafter.