A third of students say they've been bullied in the past month.
The first International Day Against Violence and Bullying in Schools also shows cyber-bullying is on the rise.
Last year, UNESCO declared that on the first Thursday of November all countries should highlight bullying. Their overall aim is to eventually eliminate it from schools.
Research shows one in three students have been bullied in the past month. Students who are bullied are also around twice as likely to have contemplated suicide as those who are not bullied.
Meanwhile, one in 10 children have been targeted online.
UNESCO says reducing school violence and bullying is possible, and robust policy frameworks, teacher training and curriculums that a caring school climate can help.