Previous research has suggested that bullying is an increasingly severe problem in schools. Such research has approached the phenomenon from two different angles. Earlier research has treated bullying and victimisation as separate entities. However, current research suggests that bullies and victims engage in a special dynamic and interactive relationship, thereby providing the need for studying any similarities and differences between bullies and victims in relation to various factors. The present research has approached bullying and victimisation in both ways. First, we studied differences between bullies, victims, and those not involved in relation to various demographic, school, well-being, and personality factors to identify factors that separate these three groups. In addition, we studied differences between those involved in bullying/victimisation (one group) and those never involved in relation to the same aforementioned factors to highlight aspects of the development of their special relationship (i.e., common factors). Prevalence rates and types of bullying/victimisation experienced/expressed in Scottish schools were also investigated. It was found that bullying and victimisation, when treated as separate entities, differed in relation to peer self-esteem, with bullies reporting higher levels of peer self-esteem than victims. When bullies and victims were treated as one group (involved), they were found to differ from the noninvolved group in relation to various factors, including school, well-being, and personality factors. The involved group was found to be disadvantaged in relation to all measures used. However, overall results indicated that from all these factors the best predictors of overall involvement as bully, victim, or bully-victim were Quality of School Life and school stress. The present results support the notion that bullying and victimisation could be treated, by future research, as both separate and/or interactive entities. This is so because bullying and victimisation were found to differ in relation to one personality factor, that is, peer self-esteem. However, Quality of School Life and school stress, both school factors, were found to be associated with the phenomenon as a whole. Results are discussed in relation to future development of antibullying policy in Scottish schools.Aggr. Behav. 28:45–61, 2002. © 2002 Wiley-Liss, Inc.