This three year longitudinal study of a sample of CAB clients in Wales was made possible through joint funding from the Objective One European Social Fund (ESF), Citizens Advice Cymru, and facilities provided by Bangor University, including, in particular, academic advice, supervision and support. The project was also guided throughout by a Research Steering Committee made up of representatives of all the interested parties. The aims of the research were to measure the long-term impact of advice-giving on clients who had approached Citizens Advice with one or more problems. Citizens Advice is an independent charity operating as Citizens Advice Cymru in Wales. It is the membership organisation for 31 member Citizens Advice Bureaux (CABx) in Wales, which deliver advice services from 50 main offices and 154 secondary advice outlets, these include a range of community settings such as high street offices, GP surgeries, health centres, libraries, courts and also offering home visiting services. Each CAB also offers access to services by telephone. The Twin Aims of the service are to provide the advice people need for the problems they face and to improve the policies and practices that affect people's lives. Adopting a quantitative longitudinal approach, this thesis provides evidence of improvements that occurred over time in clients' health, their financial and material wellbeing, and their quality of life as a direct outcome of the advice and support they received for their problems. Implications for service delivery arise from findings that highlight the complexities of the lives of many clients. Drawing on the issues raised, a number of practical and policy recommendations are provided that focus in particular on aspects of the CAB service most valued by those experiencing serious and persistent financial difficulties.