Evidence indicates that peer victimization is predictive of later maladjustment, but the mechanisms by which harassment impairs development have yet to be identified. The objectives of this study were (a) to discern normative trends in peer victimization experiences and self- and peer perceptions during preadolescence and (b) to investigate associations between individual differences in these trajectories and changes in psychosocial adjustment. A sample of 381 children (196 girls; 185 boys) was followed longitudinally between the ages of 9 and 11 years. Latent growth curve analyses revealed that, although children's self-appraisals became increasingly positive during preadolescence, their appraisals of peers became more negative. Moreover, analyses supported the contention that self- and peer beliefs act as mechanisms through which victimization is related to psychological dysfunction.