Misbehaviour in high school impacts learning and instruction in the classroom as well as the educational climate of the institution. In this report, changes in administrators', teachers', and students' reports of misbehaviour between 1990 and 2002 were examined using two national US databases. There was little change in administrators' perspectives on the severity of misbehaviours, with some reported increase in verbal abuse of teachers and decrease in alcohol use. School urbanicity was not related to administrator reports of misbehaviour. Students reported less fighting and skipping class in 2002, but an increase in disruptions by other students and drug availability was found. (Contains 4 tables.)