Background: Background: To examine the value of speckle tracking echocardiography to detect the presence, extent and severity of coronary artery affection in patients with suspected coronary artery disease.. This study aimed to examine the value of speckle tracking echocardiography to detect the presence, extent and severity of coronary artery affection in patients with suspected CAD. Methods: This cross-sectional study enrolled 200 candidates with suspected coronary artery disease. Patients were subjected to speckle tracking echocardiography and coronary angiography. Global longitudinal peak systolic strain were assessed and were correlated to the results of coronary angiography for each patient. Results: ROC analysis was done for GLPSS in predicting single-vessel affection. It revealed a significant AUC of 0.713, with a 95% confidence interval ranging from 0.555-0.871 (P = 0.013). The best cutoff was ≤- 18, at which sensitivity and specificity were 83% and 53.8%, respectively. ROC analysis was done for GLPSS in predicting multi-vessel affection. It revealed a significant AUC of 0.908 (P < 0.001). The best cutoff was ≤ - 11, at which sensitivity and specificity were 87.7% and 89.6%, respectively. Conclusion: Two-dimensional speckle tracking echocardiography has good sensitivity and specificity to predict the presence, extent and severity of CAD.