Abstract Extant research has revealed the influence of family incivility on adults in the work context, leaving the reactions of adolescent victims unexplored. According to the frustration-aggression theory, it is possible that individuals become hopeless after experiencing such chronic low-intensity deviant behaviors in the family, thereby engaging in aggression. Considering adolescents' active participation online and their preference for covert ways to vent negative emotions, we focused on their cyberbullying perpetration rather than offline aggression. The participants were 3030 adolescents (57% girls, M age = 16.65 years) of a high school in China. The results examined the mechanism through which family incivility was significantly related to cyberbullying through the mediation of hopelessness, suggesting a strong link of real-life experience to online behavior, while emotional intelligence acted as a buffer against the relationship between family incivility and hopelessness as well as that between family incivility and cyberbullying. The findings revealed the durative underlying detriment of family incivility, and cyberbullying prevention strategies were proposed. Both theoretical and practical implications of these findings were discussed.