Introduction:The aim of the current study was to assess the impact of an intervention aimed at communicating the negative reinforcement explanation for smoking, a set of ideas derived from popular self-help books, upon participants' cognitions and urges to smoke. Methods: Smokers (n = 205) undergoing standard stop-smoking treatment were randomised to receive either the experimental intervention, a brief intervention aimed at communicating the explanation or a control intervention, a video on the health risks of smoking. Outcomes were participants' acceptance of the negative reinforcement explanation for smoking, positive outcome expectations for smoking, self-efficacy and urges to smoke reported at one week post-cessation. Results: Post-cessation urges to smoke were similar in the two groups (Adjusted expt. group mean = 2.50, Control group mean = 2.75, F(1,60) = 0.98, p = .33). Other cognitive measures were also unchanged. Conclusions: The brief cognitive intervention offered as an adjunct to standard care failed to reduce urges to smoke or alter smokers' cognitions. Changing smokers' cognitions may be as challenging as changing their behaviours. Suggestions are provided for further research.