The purpose of the present study was to investigate the direction of effects between parents’ sources of knowledge and children’s involvement in bullying and victimization at school. The participants were 348 early adolescents with a mean age of 13.5 years and their mothers. The children completed the Revised Bullying and Victimization Questionnaire, while the mothers completed the Parental Knowledge Questionnaire. Data were collected in two time points with a 6-month interval. The structural equation model showed that child disclosure and parental control at Time 1 (T1) positively predicted bullying at Time 2 (T2), while parental solicitation at T1 negatively predicted bullying at T2. Conversely, bullying at T1 positively predicted child disclosure and parental control at T2, while victimization at T1 positively predicted parental solicitation at T2 and negatively predicted child disclosure at T2. The results confirmed that the relationship between parental knowledge and bullying is reciprocal and that prior parental solicitation was the only source of knowledge that was negatively related with future involvement in bullying. Interestingly, victimization at T2 was not related with any of the sources of parental knowledge at T1 indicating that parents’ effort to know about their youths’ socialization may not lead to reducing victimization. Bullying, however, appeared to be negatively predicted by prior parental solicitation indicating that parents’ effort to know who their children socialize with may indeed operate as a protective barrier. Finally, our study showed that prior victimization is related with less child disclosure, which confirms the assumption that victimized children often hide their experience from their parents.