This research has been motivated by a lack of studies related to cyberbullying in Montenegro. The main goal of the research has been to evaluate the incidence of cyberbullying and its most common forms among high school students in Montenegro, as well as whether it is committing and experiencing cyberbullying connected to the self-esteem of high school students. As many as 202 students from 10 Montenegrin high schools have participated in the research. Schools from the northern, central, and southern regions of Montenegro have been included. The research results analysis has shown that high school students commit and experience various forms of cyberbullying. The results have shown that, when it comes to committing it, the most common forms are online ridicule and online identity concealment, while the least common are e-mail insults, as well as online fraud. When it comes to experiencing cyberbullying, based on the data analysis, we can conclude that the most common forms among high school students are online gossip/slander, spreading online rumors, and online identity concealment. According to the results of our research, high school students experience online fraud and e-mail insults the least. As for the connection between committing and experiencing cyberbullying and self-esteem, we have concluded that there is a statistically significant connection between committing and experiencing verbal cyberbullying and online counterfeiting/criminal acts since high-school students committing and experiencing verbal cyberbullying and online counterfeiting/criminal acts possess higher self-esteem than those uninvolved. However, the level of self-esteem is quite low over the whole sample. Committing and experiencing online identity concealment/lies are not related to low self-esteem in high-school students.