This Health Psychology Doctoral Thesis is twofold. The research component presents three studies in the field of smoking cessation. Two of the studies look at psychosocial and physical addiction factors and its relationship with making a decision to quit smoking and maintaining abstinence. The third study explores the validity and effectiveness of a NHS approach to a Brazilian population. An emerging theme from the studies is that even though the current approach employed by the NHS is effective on the short-term it is also far too generic failing to address important needs of specific populations. The practice component presents case studies in core competencies in health psychology including consultancy, behaviour change interventions, directing interventions and a systematic review. This professional doctorate thesis presents a critical review of the approaches employed in the UK to smoking cessation