Many surveys confirm a substantial number of discipline problems in schools, but not many surveys are aimed at their identification. Identification of discipline violations is indispensable for prudent planning of their interventions in and prevention of their occurrence. Earlier studies focused mostly on the teachers' perceptions of discipline problems and they were not interested in how discipline problems are perceived by students. In this study, teachers and students identified the most frequent and disturbing discipline violations. Given the results of the survey, it would be necessary to pay more attention to preventing disruption of lessons and improper attitude, which are, in the views of teachers and students alike, the most frequent and disturbing violations.