© 2017 Society for Research on Adolescence This study examined trajectories of victimization and problem behaviors within and across three grades of middle school. Participants were 2,166 adolescents from three urban middle schools in the United States who completed measures of victimization, physical and relational aggression, substance use, and delinquent behavior. Latent curve analyses modeled changes in each construct across 12 waves collected every 3 months. In each case, the best-fitting model required separate linear slopes to represent changes within each grade and a factor representing decreases in the summers. Positive cross-construct correlations were found for intercepts, linear slopes, and measures within waves. The findings suggest strong associations among victimization and problem behaviors, and individual differences in their patterns of change both within and across grades.