Objective The purpose of this paper is to assess whether smokers adjust their beliefs in a pattern that is consistent with Cognitive Dissonance Theory. This is accomplished by examining the longitudinal pattern of belief change among smokers as their smoking behaviours change.

Methods A telephone survey was conducted of nationally representative samples of adult smokers from Canada, the USA, the UK and Australia from the International Tobacco Control Four Country Survey. Smokers were followed across three waves (October 2002 to December 2004), during which they were asked to report on their smoking-related beliefs and their quitting behaviour.

Findings Smokers with no history of quitting across the three waves exhibited the highest levels of rationalisations for smoking. When smokers quit smoking, they reported having fewer rationalisations for smoking compared with when they had previously been smoking. However, among those who attempted to quit but then relapsed, there was once again a renewed tendency to rationalise their smoking. This rebound in the use of rationalisations was higher for functional beliefs than for risk-minimising beliefs, as predicted by social psychological theory.

Conclusions Smokers are motivated to rationalise their behaviour through the endorsement of more positive beliefs about smoking, and these beliefs change systematically with changes in smoking status. More work is needed to determine if this cognitive dissonance-reducing function has an inhibiting effect on any subsequent intentions to quit.