Part I is an overview of what is known about bully/victim problems among school children. This information consists primarily of the findings from four of the author's own research projects. One of the studies is a longitudinal or followup project that involves some 900 boys from Greater Stockholm, Sweden. The research was begun in the early 1970's and is still continuing. Part II presents the intervention program that the author helped develop. This section provides information on how bully/victim problems can be addressed and counteracted in the school, in the class, and in contact with individual students. Part III summarizes the positive effects of the intervention program, based on an evaluation over a 2-year period in 42 schools in Bergen, Norway. Some of the key principles that guided the program's development are also presented. Part IV offers additional practical advice for the implementation of the program at a particular school. It specifies a set of possible core components of the program. The book also contains a guide for the identification of possible victims and bullies. It presents signs or symptoms that may help teachers and parents identify children who are victimized or who bully other students. 75 references and a subject index