Background and Aim Predicting culprit lesions in acute coronary syndrome (ACS) could be a challenge. The aim of this study was to assess the accuracy of regional wall motion abnormalities (RWMA) using various echocardiographic techniques and ECG changes in predicting the culprit coronary lesion in a group of patients with ACS. Methods In 80 consecutive patients with ACS (age 55Á7 AE 9Á4 years, 77% male, 15% with CCS Angina III), an echocardiographic examination of left ventricle (LV) RWMA, tissue Doppler imaging (TDI) and speckle tracking myocardial strain and strain rate (SR) were performed before intervention. Results Of the 80 patients, one-vessel stenosis (>70%) was present in 53 (66%), two-vessel disease in 12 (15%) and multivessel disease in 15 patients (19%). About 51% of patients had hypertension, 40% diabetes and 23% dyslipidaemia. There was no relationship between individual segmental RWMA and SR. Mean regional SR, but not peak strain, correlated with culprit lesion branch: left anterior descending -LAD (r = 0Á35, P = 0Á005), circumflex LCx (r = 0Á32, P = 0Á03) and right coronary RCA (r = 0Á37, P = 0Á01). Only ECG changes in the LAD territory (r = 0Á26, P = 0Á04) correlated with the culprit lesion. SR of LAD territories ≤À0Á74 was 71% sensitive and 70% specific (AUC = 0Á70, CI = 0Á67-0Á93, P = 0Á01), SR of LCx territories of ≤À0Á67 was 75% sensitive and 63% specific (AUC = 0Á72, CI = 0Á58-0Á87, P = 0Á02) and SR of RCA territories ≤À0Á83 was 73% sensitive and 71% specific (AUC = 0Á80, CI = 0Á66-0Á93, P = 0Á001) in predicting significant stenosis. SR was more accurate than all other techniques in predicting the culprit lesion. Conclusion In ACS, mean regional speckle tracking SR is more sensitive than peak strain, TDI, ECG changes and wall motion abnormalities in detecting significant coronary artery stenosis.