Psychosocial risk factors, such as perceived stress, not only increase the risk of cardiovascular disease, but also act as barriers for treatment adherence and cardiac rehabilitation. In this study, we examined the predictive role of perceptions for illness to perceived stress in Iranian patients participating in a cardiac rehabilitation program. A cross-sectional study was conducted in 2017 to determine correlations of demographic variables and domains of illness perception with perceived stress, and to develop a predictive model for perceived stress. In total, 150 patients with cardiovascular disease, who were admitted to a cardiac rehabilitation center, completed the questionnaires. (i) demographic and health-related characteristics; (ii) the Perceived Stress Scale-14; and (iii) the Brief Illness Perception Questionnaire. The mean perceived stress was 16.2 (8.4), and five illness perception subscalestimeline, personal control, treatment control, understanding and emotional responsewere associated with increased perceived stress. Variables in the multi-variate predictive model accounted for 48% of the total variance in perceived stress. The results demonstrated the value of assessing and managing the patients' perceptions of illness to reduce their perceived stress, which could support adherence to cardiac rehabilitation programs. K E Y W O R D S cardiac rehabilitation, cardiovascular, Iran, psychosocial risk factor, stress