Since the Second World War, there has been a striking rise in crime in the UK which can partly be explained by the increase in problem behaviours among young people. This is paralleled by a rise in the prevalence of other psychological disorders among young people, including alcohol and drug abuse, depression and suicide. This longitudinal study aims to further understanding of criminal offending among young people, particularly differential offence rates and patterns between males and females. Three main contexts will be examined: the individuals development through the life course; the impact of interactions with formal agencies of social control and law enforcement; and the physical and social structure of their neighbourhoods. A cohort of around 4,000 children starting secondary school in Edinburgh in 1998 will be surveyed each year on relationship, lifestyle and crime issues. Information on cohort members will also be collected annually from school, police, social work and Scottish childrens hearing system records. Interviews with a sub-sample of cohort members will be conducted, including some frequent or serious offenders. A Geographic Information System will examine crime patterns within Edinburgh in the context of other social and geographical characteristics, allowing more detailed study of two Edinburgh neighbourhoods.