Background: Stable angina pectoris is a common disease that may cause disability. Echocardiography is the leading and feasible cardiac imaging in patients with cardiac disease. An early evaluation of patients with complex coronary lesions plays an important role in the prognosis and selection of treatment strategy. Objective: To evaluate the feasibility and accuracy of 3D-speckle tracking echocardiography in assessment of coronary artery disease severity in stable angina pectoris. Patients and methods: The study was across sectional study include 90 patients with chronic coronary syndrome(stable angina) come to Islamic cardiac center at Al-Azhar University for coronary angiography on clinical basis indications between period from April 2019 to May 2020.The patients were classified into two groups after according to the results of coronary angiography. Group (I): Case group include 60 patients with different coronary lesions in angiography, and Group (II): control group include 30 patients with normal coronary angiography. The group (I) subsequently divided into two subclasses after coronary angiography according to the Gensini score. Group (IA) non-critical stenosis ( 0-19) , group (IB) critical stenosis (≥ 20). Results: There was no statistically significant difference between patients and control groups as regard demographic data and risk factors( age , gender, diabetes mellitus, hypertension, smoking ,family history and dyslipidemia) .There was no statistically significant difference between  group   (I) &group(II) as regard their Echo parameters  left atrial diameter ( LAD) , left ventricular end diastolic diameter (LV EDD), left ventricular end systolic diameter (LV ESD) , left ventricular end systolic volume (LV ESV )and left ventricular ejection fraction (LV EF%) . There was statistically significant decrease  in  group(I)  compared to group(II)  as regard their 3D speckle parameters global longitudinal strain ( GLS%)( -12.35% ± 2.7% versus -20.2% ±1.19%) , global circumferential strain( GCS%)(-19.23% ± 4.18% versus -26.57% ± 1.3%), global radial strain (GRS% )(23.48 ± 3.32% versus 53.67% ± 2.99%) and global area strain (GAS%)(-23.98% ± 4.14% versus -31.93 ± 1.28%) . Also there was significant decrease in critical stenosis group (IB) as regard 3D speckle parameters in comparison with non-critical stenosis group (IA). Conclusion: 3D-STE is a noninvasive and handy parameter that has the potential to improve the value of echocardiography in the detection of the coronary artery disease (CAD) and to provide more information for clinical physicians. It could be expected to identify severe coronary stenosis in chronic coronary syndrome (CCS) patients even when resting wall motion and left ventricular ejection fraction were normal. It shows good sensitivity and specificity with best values for global area strain (GAS).