Purpose of review Antisocial behaviour and mental illness in adulthood place a high social and financial burden on societies. Rapidly developing knowledge base about both, whether the natural history, overlap, or the increasingly promising findings of evidence based results from prevention, early and late intervention programmes, delivered to children and adolescents, in the context of family, community and institutions, can reduce the burden on adult services, and is the focus of this review. Recent findings Established and new longitudinal studies continue to enrich and inform the "What Works" literature, addressing how to target and deliver programmes and to better engage difficult to access children and families. A needs led, holistic approach is assisting in understanding the complex interplay between antisocial behaviour and mental illness in juveniles. Research on the impact of correctional institutionalization on vulnerable young people, impact of trauma on offending patterns and the importance of linking the institutional and community components of treatment programmes can assist practitioners in how best to deliver services. Treatment for young sexual abusers now recognises the differential presentation of abusive behaviour through childhood and adolescence. Substance misuse, its risks to the young person, and its influence on their offending remains a major challenge even with sophisticated treatment options such as multisystemic therapy. The approach to use of medication in childhood aggression is markedly different in the USA and UK and Europe. Recent research on personality development in adolescence and the trajectory into adult antisocial personality disorder, is not teasing out factors and processes that can be used constrictively in practice interventions for violence and aggression in young people. A developmental underpinning is now informing child and adolescent risk assessment tools. Summary The recent evidence base in the field of child and adolescent forensic mental health and juvenile justice is starting to make a real difference to clinical practice, pointing to practice that can offer multiple interventions at multiple points across the childhood years, and on into adult forensic practice.