The purpose of this study was to test bidirectional relationships between (cyber)bullying and (a) bonding to school and (b) bonding to teachers. These relationships were examined while controlling for traditional and cyberbullying victimization, as well as gender and age. The sample consisted of 2,128 Belgian early adolescents, who participated in a two-wave panel study with a 6-month time interval. The data were analysed using cross-lagged panel analyses. The results indicate the robust temporal stability of being bonded to school and teachers, bullying perpetration (traditional and cyber), and bullying victimization (traditional and cyber). For teacher bonding, a small negative bidirectional relationship was found with cyberbullying perpetration. Low levels of teacher bonding at Time 1 predicted subsequent cyberbullying at Time 2; cyberbullying at Time 1 led to later poor teacher bonding at Time 2. On the other hand, the expected longitudinal associations between school bonding and (cyber)bullying perpetration were not confirmed. The results of the current study implicate that a positive bonding to teachers in particular could be a protective factor against bullying via the Internet or mobile phone. Further implications of these results for prevention and intervention with regard to (cyber)bullying are discussed.