Planning is regarded as highly valuable in the process of health behaviour change. It bridges the gap between behavioural intentions and health behaviour. To further develop this concept, a distinction is made between action planning and coping planning. The latter refers to the mental simulation of overcoming anticipated barriers to action. Action planning and coping planning for physical exercise were examined in a longitudinal study with 352 cardiac patients. They were approached during rehabilitation treatment and followed up at two and four months after discharge. Both planning cognitions were psychometrically identified, and it was found that they operated differently in the behavioural change process. Action plans were more influential early in the rehabilitation process, whereas coping plans were more instrumental later on. Participants with higher levels of coping planning after discharge were more likely to report higher levels of exercise four months after discharge. It is suggested to include both kinds of planning in interventions at different stages in health behaviour change. Copyright © 2005 John Wiley & Sons, Ltd.