This study used latent class analysis to examine the trajectories followed by young people's educational aspirations in England over the age range from 13 to 16 years and their relationship to educational achievement. The results suggested that young people's aspirations followed six trajectories. Four trajectories showed overall patterns of aspirations which did not vary over time, while in the two remaining trajectories, aspirations either moved upwards or downwards. The trajectories were stratified according to young people's family background and individual characteristics with those trajectories with high aspirations having higher proportions of young people from better-off family backgrounds and a higher proportion of girls and respondents from ethnic minority backgrounds. Respondents with high aspirations made more progress in achievement and had a higher likelihood of admission to university than those with low aspirations. Differences in aspirations did not completely explain differences in educational achievement by family background, however.