Intimate partner violence is an important public health problem. Cyber dating violence (CDV) is a form of intimate partner violence perpetrated within a dating relationship via new communication technologies. This study investigated the moderating roles of hostile and benevolent sexism in the relationship between problematic pornography use and CDV perpetration. The Cyber Pornography Use Inventory, the Cyber Dating Violence Inventory, and the Ambivalent Sexism Inventory were completed by 421 Italian adolescents (M = 16.53; females = 63.7%). Results indicated that problematic pornography use was positively related to CDV perpetration. In addition, the relationship between problematic pornography use and CDV perpetration was found to be moderated by hostile sexism. In participants with low levels of hostile sexism, the relationship between problematic pornography use and CDV perpetration was not significant. Conversely, in those with high levels of hostile sexism, this relationship was stronger and significant. Benevolent sexism was not found to be a moderator in the relationship between problematic pornography use and CDV perpetration. Thus, hostile sexism could be a risk factor for the relationship between adolescents' problematic pornography use and their engagement in CDV. Conversely, low levels of hostile sexism could be a protective factor.