Bullying is usually defined as the repeated oppression of a less powerful person by a more powerful one. This definition includes three key elements: (1) physical, verbal, or psychological attack intended to cause distress or harm to the victim; (2) imbalance of physical or psychological power; and (3) continuous series of incidents between the same people over a prolonged period of time. Research indicates most school children are involved in bullying behavior, either as bullies or as victims. Bullies tend to be aggressive, tough, strong, confident, and impulsive, while victims tend to be unpopular, lonely, rejected, anxious, depressed, unwilling to retaliate, and lacking in self-esteem. In the current research, a self-report questionnaire was developed to assess bullying and victimization among incarcerated young offenders in Ontario. Two pilot studies were conducted in 1992 and 1993 at an open custody facility for young offenders. Preliminary results based on a small sample of 20 young male offenders showed most residents (70 percent) were involved in bullying several times a week or more often, either as bullies (45 percent) or as victims (25 percent). It was determined that the anonymous, group-administered, self-completed questionnaire may not be the best method for collecting data on bullying in young offender institutions and that more complete and valid data can be obtained by asking questions in the context of an individual interview. Further research is recommended to investigate when and where bullying occurs, how different institutions vary in the prevalence of bullying, and the extent to which variations reflect characteristics of youth as opposed to features of the institutions themselves. The bullying interview schedule is appended. 49 references and 2 tables