The intent of this longitudinal, multi-method, multi-agent study was to examine changes in bullying, victimization, and aggressive victimization as well as changes in peer affiliation as youngsters made the transition from primary school through the first year of middle school. Results indicated that bullying and aggressive victimization were relatively stable across time, possibly due to temperamental factors. Changes in peer affiliation indicated that youngsters' casual contacts with peers initially decreased from primary to the beginning of middle school but recovered by the end of the year. Close relationships, however, decreased, and number of youngsters nominated as isolates increased. Being embedded in an affiliative network of peers, in turn, inhibited victimization. School environmental factors did not make significant contributions to bullying or victimization. Results are discussed in terms of the importance of social affiliations in minimizing victimization in early adolescence. Limitations of the research were noted and suggestions for future research were also made.