Social media is widely used by university students in modern times, although, serious psychological damage is caused to users through cyberbullying activities. This study examined the relationship between social media use and students' cyberbullying behaviors in a west Malaysian public university. Correlational survey was adopted, while 400 undergraduates purposively selected from three faculties participated in the study. Questionnaire entitled "Engagement on Social Media Use (ESMU)" was used for data collection. Two hypotheses were tested using SEM-PLS3. Results indicated that social media use and gender significantly related to cyberbullying behaviors. Counseling is recommended to assist in stemming cyberbullying behaviors among undergraduates.