Little is known about the levels and psychological consequences of bully/victim behaviours in schools in Northern Ireland. The aim of the present study was to examine the prevalence of self-reported experiences of school bullying, and the relationship between such experiences, stress and general psychological health. A random sample of 824 twelve- to seventeen-year-olds living throughout Northern Ireland completed a questionnaire booklet as part of the 2004 “Young Life and Times” survey. Respondents completed a bullying-related question, two stress-related items, and the GHQ-12. The data indicate that bully/victim problems are pervasive in Northern Ireland’s schools, with 13% reporting being bullied 'sometimes', 'often', or 'always'. Also, involvement in bully/victim problems was associated with impaired psychological health in terms of increased stress and lower general psychological well-being. These findings are discussed within the context of the wider international literature on bullying.