Background & Objective: Heart disease is caused by coronary artery stenosis is a health problem in developing and developed countries. The disease is one of the leading causes of death in the world. Acceptance and commitment therapy (ACT) is a form of counselling and a branch of clinical behavior analysis. It is an empirically–based psychological intervention that uses acceptance and mindfulness strategies mixed in different ways with commitment and behavior–change strategies, to increase mental flexibility. There is a variety of protocols for the ACT, depending on the target behavior or setting. For example, in behavioral health areas, a brief version of ACT is called focused acceptance and commitment therapy (FACT). The goal of ACT is not the elimination of complicated feelings; instead, it is to help us to move toward valued behavior. Acceptance and commitment therapy invites people to accept unpleasant feelings, and learn do not to overreact to them and not to avoid those situations. The therapeutic effect of the method is like a positive spiral; feeling better leads to a better understanding of the truth. In the ACT, 'truth' is measured through the concept of 'workability'. Coronary heart disease (CHD) is among the conditions that affected by psychological factors. The purpose of this study was to investigate the impact of acceptance and commitment therapy in illness perception in male patients with cardiovascular disease.
Methods: The research method was quasi–experimental study with two groups (experimental and control) pre–posttest design. The statistical population comprised men with cardiovascular disease admitted to the heart clinic of Valiasr Hospital in Qaemshahr (Mazandaran province, North of Iran) in the spring of 2017–2018. A total of 28 subjects were voluntarily chosen and were randomly assigned into two experimental (n=14) and control (n=14) groups. The experimental group received six session acceptance and commitment therapy (ACT). Brief illness perception questionnaire (Brief IPQ) was administered before and after training. The data was analyzed using one–way analysis of covariance (ANCOVA). 
Results: The results indicated that in the post–test after controlling the pre–test, there was a significant difference between the experimental and control groups in illness perception (p=0.032). 
Conclusion: Acceptance and commitment therapy could reduce the perception of disease in patients with heart disease.