Cyber dating abuse is a new kind of dating violence. Several recent measures assess this phenomenon, but do not focus on a severe aggression that aims to spoil a partner’s relational network (relational cyber abuse). This study developed and validated the Cyber Dating Violence Inventory (CDVI) with 1405 adolescents and young adults (M_age�=�18.17; SD_age�=�2.39; 65.1% females), an instrument that considers the relational dimension of online dating abuse. Exploratory and confirmatory factor analyses found two correlated factors (Psychological and Relational) for both perpetration and victimization, showing good reliability. CDVI factors were positively correlated with offline dating violence, showing good criterion validity. This instrument has clinical and educational implications.