Young people excluded from mainstream schooling are a vulnerable group who are at a high risk of experiencing social disaffection and are more likely to find themselves involved in anti-social behaviour. During the 1990s, Northern Ireland experienced increasing levels of illicit drug use, particularly among young adults and adolescents. The present paper examines existing empirical evidence for an association between these behaviours and school exclusion. The evidence has been obtained from studies carried out mainly in England and Wales, as such evidence appears non-existent in Northern Ireland to date. The paper also argues that the existence of this group of young people requires more in-depth qualitative research now that the Department of Education have begun to monitor their existence more systematically. This will help identify the full extent of the problem, particularly as existing empirical evidence shows the size of this group to be increasing in recent years. This complies with the Labour Government's social inclusion initiative advocated by the Social Exclusion Unit, but one that remains, as the present paper suggests, underdeveloped in Northern Ireland.