Although previous research has demonstrated that the experience of cyberbullying victimization is associated with behavioral and psychological health problems, it is still unclear how cyberbullying victimization affects physical and mental health issues. Our aim was to test the longitudinal linkage between cyberbullying victimization and problematic Internet use (PIU) via the possible mediating roles of mindfulness and depression. This study employed a two-wave longitudinal design. 661 Chinese junior high school students were assessed using self-reported questionnaires about cyberbullying victimization, mindfulness, severity of depression, and PIU. The results revealed that the experience of cyberbullying victimization was positively related to PIU through the mediating variables of mindfulness and depression.