Background: Cardiovascular disease is the most leading cause of morbidity and mortality throughout the world today. Chronic total occlusions are defined as 100% occlusions with TIMI flow 0 with at least 3-month duration. New echocardiographic techniques is an important noninvasive method for assessing cardiovascular function and mechanics. Objective: Determination of the impact of revascularization for chronic total occlusion coronary artery disease on left ventricular function using three-dimensional and three- dimensional speckle tracking echocardiography. Patients and methods: The present study included (60) patients presenting with chronic total occlusion coronary artery disease at Al-Azhar University Hospitals, in the period between December 2015 and April 2018. The study compared the differences in echocardiographic parameters before the procedure (pre-procedure) and one month after successful PCI to CTO (post- procedure). Two-dimensional (2D) and three- dimensional (3D) transthoracic echocardiography (baseline and follow up study), 2D Global longitudinal strain (GLS) and 3D longitudinal strain (LS) speckle tracking echocardiography (base line and follow up study) were done. Results: Mean left ventricular ejection fraction significantly increased, while the left ventricular end-diastolic and end-systolic volumes significantly decreased. The left ventricular end-systolic and end-diastolic volumes and diameters were significantly decreased. The global longitudinal strain (2DSTE and 3DSTE) showed significant improvement after successful revascularization. Both patients with LVEF ≥ 50% and LVEF < 50% displayed significant improvement in the 2D GLS and 3D LS, also diabetic and non-diabetic patients displayed significant improvement in the 2D GLS and 3D LS. Improvement in the 2D GLS % was correlated with an improvement in the 3D LS %. Conclusion: Restoring the coronary blood flow in chronic total occlusion patients reduces the left ventricular volumes, dimensions and improves the left ventricular ejection fraction and global longitudinal strain of hibernating myocardium.