Adolescents' expectations about the timing of adult role transitions have the potential to shape their actual transitions, setting the stage for their adult lives. Although expectations about timing emerge by early adolescence, little is known about how these expectations develop across adolescence. This longitudinal study examined developmental trajectories of adolescents' anticipated ages of school completion, job entry, marriage, and parenthood over the high school years, focusing on gender differences. Latent growth curve analysis of data from 411 rural youths followed from Grades 9 through 12 (age at Grade 9: M = 14.35, SD = 0.77) indicated a significant increase in adolescents' anticipated ages of entry into work and parenthood as well as gender differences in the trajectory of the expected age of marriage. Gender role attitudes, school performance, romantic relationships, and expected educational and occupational attainment were associated with the anticipated timing of role transitions, with significant variations by gender. Adolescents' expected ages of entry into adult family roles predicted their educational attainment and family role transitions in early adulthood. The findings provide insights into the process through which adolescent boys and girls construct their expectations regarding the transition to adulthood and, in turn, their future life course.