This study aims to examine risk- and protective factors connected to juvenile delinquency. To accomplish this, data from the research project LoRDIA (Longitudinal Research on Development In Adolescence) will be examined, and the results will then be compared with the results from the school study done by BRÅ (The Swedish National Council for Crime Prevention). The theoretical framework of this study is based on social development theory. LoRDIA:s study is carried out on 1441 adolescents attending grades 8 and 9 between the ages of 13–17 (with an age average of 14,8 years). Also, parental monitoring and its effect on risk- and protective factors are examined. Comparisons between the two studies show that there are similarities in general, where boys as well as if the parents of the adolescent are divorced/separated exhibit greater risk associated with delinquent behaviour. Both of these risk factors are connected to a lack of parental monitoring. An insufficient parental monitoring where mainly connected to if the adolescents parents were divorced/separated and the adolescent alternated between living with its parents. The study also show that the crime rates differ between the municipalities participating in the LoRDIA:s study. All results generated by this study are of value for crime prevention in social work. Further research are however required in order to concretely implement the findings in practice.