Objective: Cyber bullying represents a new and alarming form of bullying that potentially leads to serious and long-lasting consequences for young people; yet, there is a dearth of research on the assessment of cyberbullying behaviors among emerging adults. Thus, this study aims to close this gap by assessing the development and validation of the cyberbullying behavior scales for application in social work research and practice settings. Methods: Two scales, cyberbullying perpetration (CBP) and cyberbullying victimization (CBV), were validated using a purposive sample of 286 undergraduate students aged 18 to 25. Results: Both CBP and CBV scales showed excellent reliability (a = 0.93 for CBP and a = 0.95 for CBV), good fit, and strong convergent validity. Conclusions: The cyberbullying behavior scales provide valid and reliable measures of emerging adults' bullying behaviors. Implications for further social work research and practice are discussed.