ABSTRACT Background: The reciprocal change is a surrogate marker of the severity of myocardial infarction (MI). Patients exhibiting this reciprocal change tend to have a larger infarction, poorer left ventricular systolic function, higher incidence of proximal left anterior descending artery (LAD) lesions, multivessel diseases, and worse prognosis. Objective: This study aimed to find the association between reciprocal ST segment changes and syntax score in patients undergoing primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI). Patients and methods: The study included sixty patients who were presented to Emergency Room with STEMI and underwent primary PCI. Echocardiographic evaluation was performed within 24 h of PPCI. We assessed the severity of coronary artery disease (CAD) using syntax and gensini scores. Results: There was significant difference regarding gensini score and syntax score that was higher in with reciprocal change group than without reciprocal change group. Conclusion: We concluded that there is an association between reciprocal ST segment changes and syntax score in patients undergoing primary PCI for ST elevation myocardial infarction.