School bullying victimisation is associated with poor mental health and self harm. However, little is known about the lifestyle factors and negative life events associated with victimisation, or the factors associated with self harm among boys who experience bullying. The objectives of the study were to examine the prevalence of bullying in Irish adolescent boys, the association between bullying and a broad range of risk factors among boys, and factors associated with self harm among bullied boys and their non-bullied peers. Analyses were based on the data of the Irish centre of the Child and Adolescent Self Harm in Europe (CASE) study (boys n = 1870). Information was obtained on demographic factors, school bullying, deliberate self harm and psychological and lifestyle factors including negative life events. In total 363 boys (19.4%) reported having been a victim of school bullying at some point in their lives. The odds ratio of lifetime self harm was four times higher for boys who had been bullied than those without this experience. The factors that remained in the multivariate logistic regression model for lifetime history of bullying victimisation among boys were serious physical abuse and self esteem. Factors associated with self harm among bullied boys included psychological factors, problems with schoolwork, worries about sexual orientation and physical abuse, while family support was protective against self harm. Our findings highlight the mental health problems associated with victimisation, underlining the importance of anti-bullying policies in schools. Factors associated with self harm among boys who have been bullied should be taken into account in the identification of boys at risk of self harm. (C) 2010 Elsevier Ltd. All rights reserved.