Abstract The growing prevalence of children’s mental health difficulties has gained increased attention, particularly since the pandemic. This has led to various UK government initiatives and strategies, including improving mental health support in schools, colleges, and community-based services and increasing mental health services available through private practices for children and young people. However, in an era of evidence-based practice, there is an absence of data from these services that contribute to the evidence base to understand what works for whom under specific circumstances, contexts, and therapeutic approaches. Drawing on theoretical and research foundations, this paper discusses the art and science of integrative child psychotherapy as evidence-based clinical practice. While a framework and assessment process which considers problems, processes, and mechanisms related to the internal world of a young person helps identify a treatment plan, integrative child psychotherapists must also recognise and take account of the child’s wider world: their socio-cultural environment, family, parent(s) or carer(s), impact of other professionals, and the political context in which they live. Central to integrative child psychotherapy is the underlying premise that therapeutic work with young clients is fundamentally different from that with adults and requires specific training and appropriately experienced and skilled supervision.