In this study, we aimed to evaluate the relationship between TIMI myocardial perfusion (TMP) grade, as an indicator of myocardial reperfusion, and fragmented QRS (fQRS) in standard 12-lead electrocardiogram. Also, we evaluate fQRS is an additional indicator of myocardial reperfusion. One hundred patients admitted with first STEMI to Coronary Intensive Care Unit and who were used thrombolytic therapy was included in this retrospective study. Standard 12-lead electrocardiogram records of patients simultaneous with coronary angiography (second day) were assessed and analysed for the presence of fQRS. Also, coronary angiography images were analyzed to identify the infarct related artery, TIMI grade of infarct related artery and TMP grade of infarct related artery. The patients with fQRS demonstrated a significantly lower TMP grade, TIMI grade and ejection fraction compared with the non-fQRS patients (P = 0.004, P = 0.003, P = 0.02 respectively). The patients with inadequate myocardial reperfusion demonstrated a significantly higher fQRS compared with the adequate myocardial reperfusion patients. (56.9% versus 23.5%, P = 0.002 respectively). On correlation analysis, there was a significant negative correlation between fQRS and left ventricular ejection fraction (r = -232, P = 0.02) TMP grade and adequate myocardial reperfusion (TMP 3) showed significant negative correlation with fQRS (r = -0.370, P = 0.000; r = -0.318, P = 0.001 respectively). Presence of fragmented QRS in STEMI patients was associated with inadequate myocardial reperfusion and it can be used as a simple, noninvasive parameter to evaluate myocardial reperfusion. ©2012, Wiley Periodicals, Inc.