Objectives: This study aims to determine if patients with acute myocardial infarction differ in illness perception and secondary prevention outcomes depending on the treatment they received.Methods: A repeated measures design was used to compare patients with acute myocardial infarction receiving three different treatment modalities: ST-elevation myocardial infarction treated by primary percutaneous coronary intervention,ST-elevation myocardial infarction treated by thrombolytic therapy,and non ST-elevation myocardial infarction treated by medication.A convenient sampling technique was used to recruit 206 patients with acute myocardial infarction who agreed to participate in the current study.Patients’ illness perception,physical activity,and demographical and clinical data were collected during hospital admission and again at 6 months.Results: A total of 186 patients completed the study.Results showed that the primary percutaneous coronary intervention group perceived their illness as acute rather than chronic (P =0.034) and has lower personal control (P =0.032),higher treatment control (P =0.025),and higher perception of illness coherence (P =0.022) compared with patients receiving thrombolytic therapy and treated after non-ST segment infarction.Moreover,they report low control of their blood pressure (P =0.013) and less physical activity (P =0.001).Conclusion: The results of this study revealed that patients’ treated with primary percutaneous coronary intervention had negative illness perception and limited behavioral changes 6 months after hospitalization in comparison with other treatment modalities such as percutaneous coronary intervention and thrombolytic treatment.Further research is recommended to confirm this association with longer follow-up study and among different cultures.