In the last decade, attempts have been made to improve the efficacy of minimal interventions by tailoring them to individual features. In the development of these tailored interventions, it is important to know which information in interventions is essential. Most smoking cessation interventions contain information on the outcomes of quitting and skills to be used in a quit attempt. The present study was designed to assess the cognitive changes caused by both sorts of information. Therefore, 246 smokers who were planning to quit within 6 months were randomly assigned to three different conditions. In the first condition, the respondents received a computer-generated tailored letter on the outcomes of smoking cessation. In the second condition, the respondents received a computer-generated tailored letter containing self-efficacy enhancing information, mainly on skills. In both conditions, the contents of the letters were based on the pre-test scores of the participants. Participants in the control condition did not receive any cessation information. The results show that information on the outcomes of quitting changed expected outcomes while information on coping skills changed self-efficacy expectations, in comparison with the control condition. Comparing both experimental conditions, information on the outcomes led to changes in expected outcomes, whereas information on coping skills did not lead to higher self-efficacy expectations than information on the outcomes of quitting. It is concluded that the hypothesized effects were partly verified.