The aim was to determine the factors that contribute to behavioural change in smokers, and to assess differences in the distribution of these factors between those in lower and higher stages of behavioural change using the transtheoretical model (TTM). A total of 112 participants were recruited from smoking cessation clinics in six local health authorities in North Wales, United Kingdom into a cross-sectional study; 46% of the participants were in the lower stages of the TTM (Precontemplation and Contemplation). The odds of being in the higher stage of behavioural change were not significantly associated with any of the factors considered (p > 0.05). In open-ended questions, the main factors reported to influence the decision to quit smoking were related to health and expenditure on cigarettes. The findings of this study suggest that in addition to the existing health strategy of promoting knowledge of the health impact of smoking, understanding factors influencing smokers to take steps towards quitting is also important.