Rates of child behaviour problems are increasing both in the UK and globally. Numerous risk factors for the development of child behaviour problems have been identified but a key risk factor is dysfunctional parenting practices. Parenting programmes are the most effective treatment for child behaviour problems, however barriers to treatment prevent some families, particularly disadvantaged families, from accessing programmes delivered in a group format. Individually delivered programmes eliminate some of the barriers associated with group-based programmes and may be more accessible and therefore appropriate for disadvantaged families (Chapter 1). The Enhancing Parenting Skills (EPaS) 2014 programme is an individually delivered behavioural parenting intervention for parents of young children with behaviour problems. This thesis reports on the first rigorous evaluation of the EPaS 2014 programme. Chapter two gives an overview of the origins and background of the EPaS 2014 programme followed by the first study, a systematic review of the evidence for individually delivered parenting intervention for parents of young children displaying behaviour problems (Chapter 3). Chapter four is the published protocol for the main evaluation study providing details of the methodology. Chapter five describes the baseline characteristics of a sample of families recruited for the main study. Children had high levels of co-occurring hyperactivity symptoms and parents were generally low educated, unemployed, living in poverty and had high levels of depressive symptoms. The next two chapters report the findings of the evaluation study. The EPaS 2014 programme was effective in reducing levels of child behaviour problems, especially for families who completed the intervention (Chapter 6) and feedback from health visitors was positive with all reporting they would continue to use the methods taught (Chapter 7). The final chapter of the thesis provides a summary of the research findings and discusses their implications, limitations, and future directions (Chapter 8)